Name: Slow Cooker Mongolian Beef Recipe
Prep time: 10 min
Cook time: 4 h
Total time: 4 h 10 min
Cuisine: Asian American
Ingredients: 1 ½ pounds flank steak; ¼ cup cornstarch; 2 tablespoons olive oil; 1 teaspoon garlic, minced; ¾ cup soy sauce; ¾ cup water; ¾ cup brown sugar; 1 cup carrots, grated; Green onions, for garnish; Sesame seeds, for garnish

I am so excited to share my absolute favorite Slow Cooker Mongolian Beef Recipe with you. This dish has quickly become a staple in my kitchen because of its irresistible combination of tender flank steak and a perfectly balanced sweet and savory sauce. I love how the slow cooker transforms the beef into melt-in-your-mouth goodness, making it effortless to prepare a restaurant-quality meal at home. Every time I make this, the rich flavors and aromatic garnishes have everyone asking for seconds, and I know you’ll enjoy it just as much as I do.

Why You'll Love This Slow Cooker Mongolian Beef Recipe

What makes this Slow Cooker Mongolian Beef Recipe truly special to me is the incredible flavor profile. The sauce is my favorite part—it’s sweet but not overpowering, with a deep umami taste from the soy sauce and a subtle garlicky warmth. The brown sugar gently carmelizes during the slow cooking, creating a luscious coating that clings to every tender bite of flank steak. The addition of grated carrots adds a subtle sweetness and texture that brings the whole dish together beautifully.

I also love how straightforward this recipe is to prepare. Seriously, it takes just minutes to get everything into the slow cooker, and then you’re free to go about your day while it does all the work. There’s something so satisfying about coming home to a house filled with delicious aromas and a hot, comforting meal waiting for you. It’s perfect for busy weeknights or when you want to impress guests without standing over the stove for hours.

This Slow Cooker Mongolian Beef Recipe stands out because it combines convenience with restaurant-quality flavor. Whether I’m making it for a cozy family dinner, a casual get-together, or even meal prepping for the week, it always delivers. The tender texture and rich sauce never fail to impress, and I’m betting it will quickly become one of your go-to slow cooker dinners as well.

Ingredients You'll Need

The image shows a clear plastic bag opened from the top, filled with irregularly shaped chunks covered heavily in white powder. The chunks have a rough texture with some parts showing hints of a light brown underneath the white coating. The bag is partially crumpled and placed on a white marbled surface, adding a clean and bright background that contrasts with the powdery content inside. photo taken with an iphone --ar 4:5 --v 7

The magic of this recipe comes from a handful of simple, essential ingredients that create layers of flavor and texture. Each one plays a crucial role, from the tender flank steak to the sweet brown sugar and savory soy sauce, making this dish so approachable yet delicious.

TIP : You'll find the full list of ingredients and measurements in the recipe card below

Flank steak: I prefer thinly sliced flank steak because it becomes wonderfully tender in the slow cooker.
Cornstarch: Coats the beef and helps thicken the sauce for that perfect glossy finish.
Olive oil: Adds a touch of richness and helps to marry the flavors in the sauce.

Garlic: Freshly minced for that vital punch of savory aroma and depth.
Soy sauce: The backbone of the sauce, delivering that signature salty umami flavor.
Water: Balances the strong flavors and ensures the sauce develops beautifully as it cooks.

Brown sugar: Brings a subtle sweetness that perfectly complements the savory notes.
Carrots: Grated for a natural sweetness and a pop of color and texture.
Green onions and sesame seeds: For garnish, adding freshness, crunch, and a burst of visual appeal.

Directions

Step 1: Start by cutting 1 ½ pounds of flank steak into thin strips—this helps the beef cook evenly and soak up the sauce beautifully.

Step 2: Place the steak strips in a ziplock bag with ¼ cup cornstarch. Shake the bag gently to coat every piece evenly; this step is key for that silky, thickened sauce later.

Step 3: In a medium bowl, whisk together 2 tablespoons olive oil, 1 teaspoon minced garlic, ¾ cup soy sauce, ¾ cup water, and ¾ cup brown sugar until the sugar dissolves and the mixture is combined.

Step 4: Pour this sauce mixture into your slow cooker, then add 1 cup grated carrots and the cornstarch-coated flank steak pieces. Stir gently to coat everything in the sauce.

Step 5: Cover your slow cooker and cook on high for 2 to 3 hours, or on low for 4 to 5 hours—either way, you’ll end up with incredibly tender beef and a luscious sauce.

Step 6: Once cooked, serve the Mongolian beef over steamed rice and garnish with sliced green onions and sesame seeds for that perfect finishing touch.

Servings and Timing

This recipe makes about 6 generous servings, perfect for a family dinner or leftovers to enjoy the next day. Preparation is quick and easy, taking just 10 minutes to get everything ready. The slow cooking takes 4 hours if you go low and slow, or just 2 to 3 hours if you’re short on time and use the high setting. Altogether, you’re looking at roughly 4 hours and 10 minutes total time, which is unbelievably hands-off. There’s no resting time needed once it’s done, you can serve immediately for the best experience.

How to Serve This Slow Cooker Mongolian Beef Recipe

A white bowl with a textured gray pattern holds two layers: the bottom one is plain white rice with soft grain texture, and the top one is glossy dark brown meat pieces covered in thick sauce. The meat is garnished with small, chopped green onions and sprinkled with light tan sesame seeds, adding a fresh and crunchy visual contrast. In the background on a white marbled surface, there is a small white bowl with chopped green onions. The scene includes a striped cloth partially visible at the bottom left corner. Photo taken with an iphone --ar 4:5 --v 7

When I serve this Slow Cooker Mongolian Beef Recipe, I always like to pile it on a bed of fluffy steamed jasmine or basmati rice to soak up all that amazing sauce. You could also try it with noodles or cauliflower rice if you want a low-carb option. The carrots and green onions add just the right pop of color and freshness, so I never skip the garnish—it really brightens up the plate.

For something extra special, I love adding a sprinkle of toasted sesame seeds and a little drizzle of sriracha or chili oil if I’m feeling adventurous. Pairing it with simple sides like steamed broccoli, snap peas, or a crisp Asian slaw rounds out the plate beautifully with some crunch and balance. This dish shines whether it's a casual weeknight meal or part of a festive dinner.

As for drinks, I think a cold beer, like a crisp lager or an Asian-style beer, pairs wonderfully with the sweet-savory flavors here. If you prefer wine, a slightly off-dry Riesling or a fruit-forward Pinot Noir complements the sweetness without overpowering. For a non-alcoholic option, I often go for iced green tea or ginger ale—it’s refreshing and balances the rich flavors perfectly.

Variations

Over time, I’ve tried a few variations of this Slow Cooker Mongolian Beef Recipe that I think you might love. For instance, you can swap flank steak for sirloin or skirt steak if you like, but I find flank steak’s texture unbeatable after slow cooking. If you want to keep things gluten-free, just switch the soy sauce with a gluten-free tamari sauce and double-check your cornstarch brand.

If you’re vegan or vegetarian, try substituting the beef with hearty mushrooms like portobello or king oyster, and use coconut aminos in place of soy sauce for similar umami flavor. Just keep in mind that the cooking time might shorten slightly since you don’t need to tenderize the mushrooms like meat.

For a little twist on the flavor, throwing in a splash of rice vinegar or a teaspoon of fresh ginger can add a lovely zing that lifts the dish. I’ve also experimented with cooking this on the stovetop or in an instant pot—just sear the beef strips first for extra caramelization before simmering in the sauce for 15-20 minutes. Each method yields delicious results with a slightly different texture and speed.

Storage and Reheating

Storing Leftovers

I always store leftovers in airtight containers in the refrigerator. This slow cooker Mongolian beef keeps well for up to 3 to 4 days, making it convenient for meal prep or quick lunches. Just make sure to cool it down to room temperature before sealing to prevent condensation and sogginess.

Freezing

This dish freezes beautifully. To freeze, portion out the Mongolian beef into freezer-safe containers or heavy-duty ziplock bags. Removing as much air as possible helps prevent freezer burn. It stays at its best quality for up to 3 months. When you’re ready to enjoy, thaw overnight in the fridge for best results.

Reheating

The best way to reheat leftover Mongolian beef is gently on the stovetop over medium-low heat, stirring occasionally to prevent sticking and to reheat evenly. If you prefer the microwave, heat in short bursts, stirring between, to avoid drying out the meat. Avoid boiling as it can toughen the beef and change the sauce's texture. Adding a splash of water or broth while reheating helps restore the sauce’s silky consistency.

FAQs

Can I use a different cut of beef for this recipe?

Absolutely! While flank steak is my favorite because it becomes so tender, you can also use sirloin, skirt steak, or even chuck steak if you prefer. Just make sure to slice the meat thinly against the grain for the best texture.

Is there a way to make this recipe gluten-free?

Yes! Simply replace the soy sauce with gluten-free tamari or coconut aminos, and make sure your cornstarch is gluten-free (most are, but it’s good to double-check). This way, you maintain the signature flavors without gluten-containing ingredients.

Can I make this Slow Cooker Mongolian Beef Recipe in an Instant Pot?

Definitely! Sear the coated beef in the Instant Pot using the sauté function first for added flavor, then add the sauce and cook on high pressure for about 10 to 15 minutes. Release pressure naturally for tender, flavorful beef in less time.

What can I serve with Mongolian beef to keep it low-carb?

Great question! Instead of rice, I like serving this with cauliflower rice, zucchini noodles, or steamed greens like bok choy. These options absorb the sauce well while keeping the meal light and low-carb.

How do I get the best texture on the beef?

Coating the flank steak strips in cornstarch before slow cooking is key—it helps thicken the sauce and keeps the beef tender. Also, slicing thinly against the grain makes each bite silky and easy to chew.

Conclusion

I can't recommend this Slow Cooker Mongolian Beef Recipe enough. It’s one of those dishes that feels like a hug on a plate—full of warmth, rich flavor, and comforting textures. Whether you’re feeding a crowd or just treating yourself, this recipe delivers consistently delicious results with minimal effort. Give it a try and I promise it’ll become a beloved staple in your rotation!