Slow Cooker Mongolian Beef

Tender, flavorful and delicious, this super easy Slow Cooker Mongolian Beef is only 6-ingredients and tastes just like takeout. It’s the perfect weeknight set-it-and-forget-it meal during a busy week. Everyone will love it!

Forget expensive take-out! If you’re looking for a minimal effort dinner that the family will love in the comfort of your own home, look no further than this Slow Cooker Mongolian Beef! Flank steak, cut against the grain and slow-cooked in a savory sweet sauce, comes out incredibly juicy and flavorful!

This recipe is just 6 ingredients and takes 30 minutes to prep before you let the crock pot do all the work. Anyone can master this recipe with a slow cooker, it’s so simple and your family and friends will be so impressed.

This was the third recipe I shared on Dinner in 321, and I still get messages from families saying how much they love it – it’s that popular. If you haven’t tried this dish, it’s a must! Cooking really doesn’t get much easier than this meal!

I made this and it was delicious! I added some snow peas 😄
– Nancy

Why You’ll like this Recipe

• It takes less than 10 minutes to throw together before cooking! How easy is that? You can make this any night of the week.
• It’s cheaper and yummier than take-out! When we are craving our favorite takeout on the weekends, I just whip this up instead.
• It’s the perfect meal to come home to after a long day! Nothing is better than when dinner is already prepared after a long day of work.
• The beef is melt in your mouth tender and DELICIOUS! It’s just an insane amount of flavor in every bite.

Ingredients

Scroll down to the end of this post for specific ingredient amounts in the recipe card. 

• Flank Steak: The main protein, it’s a lean cut that melts in your mouth.
• Cornstarch: Thickens the dish nicely.
• Olive Oil: The cooking oil.
• Fresh Garlic: Adds a kiss of garlic flavor.
• Reduced-Sodium Soy Sauce: Gives salty and umami notes in each bite.
• Brown Sugar or Brown Sugar Substitute: Adds a hint of sweetness.
• Shredded Carrots: Gives that brightness to the beef.
• Optional: Green Onions and Sesame Seeds for garnish. A hint of nutty and fresh flavor to add.

Tools You’ll Need

• Crockpot
• Liquid Measuring Cups
• Measuring Cups and Spoons
• Cutting Board
• Chef’s Knife

How to Make Slow Cooker Mongolian Beef

1. Cut steak into 1/2-inch strips against the grain.

2. In a Ziploc bag, add steak and cornstarch. Close and shake to coat. 

3. Add olive oil, garlic, soy sauce, water, brown sugar substitute or brown sugar, and carrots to slow cooker and stir.

4. Add flank steak and stir until coated. 

5. Cook on high 4-5 hours or on low 6-7 hours or until tender. Garnish with green onions and sesame seeds, if desired. Serve over rice, zoodles or noodles!

Pro Tips and Substitutions

• Use low sodium soy sauce. I recommend using low-sodium or reduced sodium soy sauce to ensure the recipe doesn’t taste too salty or too high in sodium. Coconut Aminos can also be used.
• Slice the steak with ease. Freezing the flank steak for 15 minutes will make it much easier to slice against the grain.
• Make it spicy! If you want to add heat, you can add crushed red pepper flakes, sriracha, hot sauce or chili oil.
• For a hint of sweetness in the sauce, brown sugar or brown sugar substitute both work in this dish.
• Swap the beef for chicken. This dish can be substituted with sliced or cubed chicken or pork tenderloin.

Storage & Freezing

After the slow cooker Mongolian beef has cooled completely, store leftovers in an air-tight container in the refrigerator up to 3 to 4 days.

Freeze leftovers in an air-tight, freezer-safe container up to 4 months. Thaw in the freezer overnight before reheating.

Frequently Asked Questions

More Easy Slow Cooker Recipes

• Crockpot Korean Beef
• Crockpot Honey Garlic Chicken
• Crockpot Garlic and Herb Pork Roast
• Balsamic Flank Steak