Slow Cooker Mongolian Beef brings the irresistible flavors of sweet soy-brown sugar glaze, minced garlic, and warming ginger right into your kitchen. Tender flank steak slices simmer in the slow cooker until meltingly soft, intermingled with crisp broccoli and vibrant red pepper for texture and color. It’s an easy weeknight dinner that feels special, bursting with fresh green onions and a hint of sesame. Grab your crockpot and get ready to impress family or friends with this fuss-free Asian-inspired feast!
Key Ingredients
Before we dive into cooking, let’s round up everything you need for this rich, flavorful dish:
- 1.5 pounds flank steak thinly sliced against the grain: Lean cut that becomes incredibly tender as it cooks low and slow.
- 1/4 cup cornstarch: Coats the beef for a light crispness and helps thicken the sauce.
- 3 tablespoons vegetable oil: For searing the steak to lock in juices and add caramelized flavor.
- 1 cup low sodium soy sauce: The savory base of the glossy Mongolian glaze.
- 1/2 cup brown sugar: Balances salty soy with sweet, creating that signature richness.
- 1/2 cup water: Helps dissolve sugar and distribute flavors throughout the sauce.
- 3 cloves garlic minced: Adds pungent warmth and depth.
- 1 tablespoon fresh ginger minced: Lends a bright, peppery zing.
- 1/4 teaspoon red pepper flakes optional: For a touch of heat when you want extra kick.
- 4 green onions sliced: Stirred in late for fresh color and light onion flavor.
- 1 teaspoon sesame oil: Drizzled at the end to boost that nutty aroma.
- 1 head broccoli cut into florets optional: Brings vibrant green color and crisp-tender bite.
- 1 red bell pepper sliced optional: Adds sweetness and a pop of red.
- 1 tablespoon sesame seeds for garnish: Toasted crunch and a pretty finish.
How To Make Slow Cooker Mongolian Beef
Slow Cooker Mongolian Beef is a breeze once everything’s prepped. You’ll start by tossing steak with cornstarch, then searing in batches to lock in those juices. Meanwhile, whisk together a balanced sauce of soy, brown sugar, water, garlic, ginger, and a hint of red pepper flakes. Layer it all in your slow cooker—veggies included if you like—and let it transform on low or high heat. With a final stir of sesame oil and green onions, you’ll have a glossy, melt-in-your-mouth dinner ready for rice or noodles.
1. Place sliced flank steak and cornstarch in a large bowl and toss until each piece is evenly coated, ensuring a light crust forms during searing.
2. Heat vegetable oil in a skillet over medium-high heat. Add steak in batches and sear until browned on both sides, about 2 minutes per side. Transfer seared steak to the slow cooker.
3. In a medium bowl whisk together soy sauce, brown sugar, water, garlic, ginger, and red pepper flakes until sugar dissolves and flavors meld.
4. Pour the sauce mixture over the steak in the slow cooker. Add broccoli and bell pepper if using for vibrant texture and nutrition.
5. Cover and cook on low for 3 to 4 hours or on high for 1.5 to 2 hours, until the steak is tender and vegetables are cooked through but still crisp-tender.
6. About 10 minutes before serving stir in sesame oil and green onions to preserve their color and fragrance.
7. Garnish with sesame seeds and serve over steamed rice or noodles for a complete meal.
Serving Suggestions
This slow cooker star shines when paired thoughtfully. Try these ideas to elevate each bite:
- Serve over a bed of fluffy jasmine rice to soak up every drop of that sweet-savory sauce.
- Plate beside stir-fried noodles, tossing them in a splash of soy and sesame oil for extra depth.
- Add a side of crunchy cucumber salad with rice vinegar, sesame oil, and a pinch of sugar to refresh the palate.
- Garnish with extra fresh cilantro or chopped peanuts for herbaceous brightness and textural contrast.
Tips For Perfect Slow Cooker Mongolian Beef
Nailing this recipe is all about layering flavors and textures, so let me share a few insider tips to get it just right:
- For a thicker sauce whisk 1 tablespoon cornstarch with 2 tablespoons water and stir in before serving.
- Skipping the searing step will save time but the beef may be less caramelized.
- Leftovers keep well in the refrigerator for up to 3 days and develop deeper flavor.
- Freeze sauce separately from beef to maintain optimal texture when reheating.
How To Store It
Keeping your Mongolian Beef fresh is simple if you follow these methods:
- Refrigerate leftovers in an airtight container for up to 3 days; the flavors deepen beautifully as it rests.
- Freeze sauce separately in a freezer-safe bag or container to prevent the beef from sogging; thaw both, then reheat gently.
- Portion properly by dividing into meal-sized containers so you only defrost what you need.
- Reheat on the stovetop over low heat or in the microwave, adding a splash of water or broth if the sauce has thickened too much.
Frequently Asked Questions
Here are some quick answers to common queries:
- What cut of beef should I use for this recipe?
Flank steak is recommended because it’s lean and becomes tender when cooked slowly. Slice it thinly against the grain to ensure each bite is tender and easy to chew.
- Is searing the beef really necessary?
Searing the beef is optional but highly recommended. It creates caramelization that adds depth of flavor and a richer color. If you skip this step, you’ll save about 10 minutes, but the beef may be less flavorful and visually less appealing.
- How can I thicken the sauce if it’s too runny?
About 10 minutes before serving, whisk together 1 tablespoon of cornstarch with 2 tablespoons of water to form a slurry. Stir it into the slow cooker and cook until the sauce reaches your desired consistency.
- Can I prepare this recipe ahead of time?
Yes. You can slice the steak and toss it with cornstarch the night before, then store it covered in the refrigerator. You can also make the sauce in advance and freeze it separately; combine and cook when you’re ready to serve to maintain the best texture.
- How long does cooking on low vs. high heat take?
On low heat it takes 3 to 4 hours for the steak to become tender and vegetables to cook through. On high heat it takes 1.5 to 2 hours. Always check the steak for tenderness before serving.
- Can I add other vegetables to the dish?
Absolutely. The recipe suggests broccoli florets and red bell pepper, but you can also use snap peas, carrots, or mushrooms. Add vegetables at step 4 so they cook but remain crisp-tender.
- How should I store and reheat leftovers?
Store leftovers in an airtight container in the refrigerator for up to 3 days. For best results, freeze the sauce separately from the beef and vegetables; this prevents the beef from becoming soggy. Reheat gently on the stovetop or in the microwave, adding a splash of water or broth if needed to loosen the sauce.
- How can I adjust the spiciness of this recipe?
The recipe includes 1/4 teaspoon of red pepper flakes for mild heat. For a spicier dish, increase the red pepper flakes to 1/2 teaspoon or add a dash of chili garlic sauce. To reduce heat, omit the pepper flakes entirely.
What Makes This Special
Slow Cooker Mongolian Beef is a magical mix of sticky-sweet glaze, tender steak, and bright veggies—plus that final pop of sesame oil and green onions that takes it over the top. It works because the slow cooker melds garlic, ginger, and brown sugar into every fiber of the meat. This is the sort of recipe you’ll want to print out, stick on your fridge, and come back to on busy weeknights. Give it a whirl, then drop a comment below with your favorite twist or any questions you have—I’m all ears!
Slow Cooker Mongolian Beef
Description
Juicy flank steak slow-cooked until meltingly tender in a glossy soy-brown sugar glaze infused with garlic, ginger, and sesame. Tossed with crisp broccoli and peppers for vibrant texture and flavor.
Ingredients
Instructions
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Place sliced flank steak and cornstarch in a large bowl and toss until each piece is evenly coated.
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Heat vegetable oil in a skillet over medium-high heat. Add steak in batches and sear until browned on both sides, about 2 minutes per side. Transfer seared steak to the slow cooker.
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In a medium bowl whisk together soy sauce, brown sugar, water, garlic, ginger, and red pepper flakes.
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Pour the sauce mixture over the steak in the slow cooker. Add broccoli and bell pepper if using.
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Cover and cook on low for 3 to 4 hours or on high for 1.5 to 2 hours, until the steak is tender and vegetables are cooked through.
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About 10 minutes before serving stir in sesame oil and green onions.
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Garnish with sesame seeds and serve over steamed rice or noodles.
Note
- For a thicker sauce whisk 1 tablespoon cornstarch with 2 tablespoons water and stir in before serving.
- Skipping the searing step will save time but the beef may be less caramelized.
- Leftovers keep well in the refrigerator for up to 3 days and develop deeper flavor.
- Freeze sauce separately from beef to maintain optimal texture when reheating.
