Ultimate Slow Cooker Mongolian Beef

Sunday afternoons in our house mean the slow cooker gets its weekly workout, usually with something that makes the whole kitchen smell like we have been cooking all day. This Mongolian beef started as a what if experiment after I ordered it at a restaurant one Tuesday night and thought I need this in my life but without the restaurant price tag. Now my husband actually asks for it by name, which is saying something for a guy who usually just says whatever you want to make is fine.

Last winter my sister came over during that awful week when everyone had the flu, and I threw this into the slow cooker because I could not stand up long enough to cook anything else. She took one bite and made me write down the recipe right there at the kitchen table, claiming it was the best thing she had eaten in weeks. Now she calls it her sick day comfort food, though honestly I make it when I am perfectly healthy too.

Ingredients

• 2 pounds flank steak, thinly sliced against the grain: This cut becomes melt in your mouth tender after hours in the slow cooker, and slicing against the grain keeps each bite from being chewy
• 3/4 cup low sodium soy sauce or tamari: The backbone of that deep umami flavor without making everything too salty
• 2/3 cup brown sugar, packed: Balances the salty soy sauce and creates that gorgeous caramelized glaze we are all here for
• 1/2 cup hoisin sauce: Adds complexity with its sweet and savory notes that make this taste restaurant quality
• 4 cloves garlic, minced: Fresh garlic beats powdered every time, and it mellows beautifully during the long cook time

Instructions

Get your slow cooker ready:

Lightly spray the inside with nonstick cooking spray so nothing sticks to the bottom during those long hours of simmering

Layer in the beef:

Arrange all those beautifully sliced flank steak pieces in the slow cooker, spreading them out so they cook evenly

Whisk up the magic sauce:

In a medium bowl, combine soy sauce, brown sugar, hoisin sauce, and minced garlic until the sugar dissolves into the liquid

Pour and coat:

Drizzle that gorgeous sauce mixture over the beef, tossing everything together so each slice gets cozy with the flavors

Let it work its slow magic:

Cover and cook on LOW for 4 hours until the beef is fork tender and the sauce has thickened slightly

Final stir and serve:

Give everything a good stir to redistribute the sauce, then serve hot over steamed rice or alongside your favorite vegetables

Pin This

The first time I made this for a potluck, I came home with an empty slow cooker and three separate recipe requests on my phone. People kept asking me what restaurant I bought it from, and when I told them my slow cooker did most of the work, they looked at me like I was hiding a professional chef in my pantry.

Making It Your Own

Sometimes I throw in sliced bell peppers during the last hour if I want to sneak in some vegetables, and they cook just enough to stay slightly crisp. My neighbor adds fresh ginger to the sauce mixture and swears it takes everything to the next level, though I have not tried that variation yet myself.

The Rice Situation

Jasmine rice is my go to because its floral fragrance pairs perfectly with the sweet and salty sauce, but brown rice works if you want something more hearty. Just remember to start your rice about 20 minutes before the beef finishes so everything hits the table at the same time.

Leftovers And Make Ahead Tips

This actually tastes better the next day when the flavors have had even more time to hang out together, which is rare for slow cooker recipes. I sometimes prep everything the night before and keep the beef and sauce separate in the refrigerator, then just dump it all in the slow cooker before I leave for work.

• Fresh green onions sprinkled on top right before serving add a bright pop that cuts through the rich sauce
• A pinch of red pepper flakes in the sauce mixture gives you that gentle heat some people crave
• Double the recipe if you are feeding a crowd because this disappears faster than you expect

Pin This

There is something deeply satisfying about coming home to a meal that smells this good and knowing dinner is already done. That moment when you lift the slow cooker lid and the sauce has thickened into something glossy and gorgeous, that is the kind of kitchen win that makes everything else worth it.

Questions & Answers

→ What cut of beef works best for this dish?

Flank steak is ideal as it becomes tender when sliced thinly against the grain and cooked slowly. Other good options include sirloin or skirt steak.

→ Can I make this gluten-free?

Yes, simply use tamari instead of soy sauce and ensure your hoisin sauce is gluten-free. The dish maintains all its flavor while being safe for gluten-sensitive diets.

→ How can I thicken the sauce?

Dissolve 2 tablespoons cornstarch in 2 tablespoons cold water and stir into the slow cooker during the last 30 minutes of cooking for a thicker, more cohesive sauce.

→ What sides pair well with this beef?

Jasmine rice is classic, but it also pairs beautifully with sautéed broccoli, steamed vegetables, or even noodles for a complete meal.

→ Can I adjust the sweetness level?

Yes, you can reduce the brown sugar by 1/4 cup for less sweetness or add a bit more for a richer flavor profile.