Mongolian Beef Slow Cooker

The first time I made Mongolian beef, I was hosting a dinner party and completely underestimated how much prep time I actually had. My friend Sarah walked into the kitchen, took one look at me frantically slicing beef against the grain, and said "let the machine do the work." That throwaway comment changed everything about how I approach weeknight cooking.

Last winter during a particularly brutal cold snap, my husband requested something warm and comforting but I had zero energy for standing at the stove. I dumped everything into the slow cooker before work, and when we walked in the door that evening, the house smelled like our favorite takeout place. Weve made it at least once a month since then.

Ingredients

• 2 pounds flank steak, thinly sliced against the grain: Taking the time to slice this properly makes such a difference in tenderness, and I learned the hard way that partially freezing the meat for 20 minutes makes it so much easier to get those thin, even slices
• 3/4 cup low sodium soy sauce: Using regular soy sauce made my first batch way too salty, so I always keep the low sodium version on hand now
• 2/3 cup brown sugar, packed: This creates that gorgeous glossy finish and balances the salty soy sauce perfectly
• 1/2 cup hoisin sauce: The secret ingredient that gives the sauce that restaurant quality depth and slight sweetness
• 4 cloves garlic, minced: Fresh garlic is absolutely worth it here, and I sometimes throw in an extra clove if Im feeling bold

Instructions

Prep your slow cooker:

A quick spray of nonstick cooking spray saves you so much cleanup time later, and I learned this trick after spending twenty minutes scrubbing dried sauce off my insert

Layer the beef:

Add all those beautiful thin slices to the slow cooker, and do not worry about arranging them perfectly they will cook down significantly anyway

Whisk the sauce:

Combine the soy sauce, brown sugar, hoisin, and garlic in a bowl until the sugar has mostly dissolved, and I usually give it a taste at this point to adjust the sweetness

Coat everything:

Pour that gorgeous sauce over the beef and toss it gently until every piece is coated, and this is when your kitchen will start smelling amazing

Let it cook:

Cover and cook on LOW for 4 hours until the beef is fork tender and the sauce has thickened into something silky and rich

Finish and serve:

Give everything a good stir before serving over steamed rice, and watch how quickly everyone gathers around the table

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My teenage daughter, who normally survives on pasta and grilled cheese, actually asked if I could teach her how to make this recipe. That was the moment I knew this wasnt just another dinner recipe it was becoming part of our family story, something she might eventually make in her own kitchen someday.

Making It Your Own

Ive found that adding sliced bell peppers during the last hour of cooking gives it such great color and a nice crunch. Sometimes I throw in snap peas or broccoli too, especially when I want to stretch the recipe to feed unexpected guests.

The Thickening Trick

If you are like me and prefer a thicker sauce that really clings to the beef, whisk together 2 tablespoons cornstarch with 2 tablespoons cold water and stir it in during the last 30 minutes of cooking. It transforms the sauce into something glossy and restaurant quality.

Serving Suggestions

While steamed jasmine rice is the classic pairing, I have also served this over cauliflower rice when I am watching my carbs, and it is still incredibly satisfying. The sauce is just that flavorful.

• Sprinkle sliced green onions and sesame seeds on top for a pop of color and fresh flavor
• A pinch of red pepper flakes adds just enough heat to cut through the sweetness
• This reheats beautifully for lunch the next day, if you actually have any leftovers

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There is something so satisfying about a recipe that delivers such incredible flavor with so little effort. Those busy weeknight moments when you can still put something special on the table, that is the real magic here.

Recipe Q&A

→ Can I use a different cut of beef?

Yes, you can use sirloin or ribeye instead of flank steak. Just be sure to slice against the grain and adjust cooking time as needed for tenderness.

→ How do I make the sauce thicker?

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 sauce.

→ Is this dish gluten-free?

Yes, simply use tamari or gluten-free soy sauce and ensure your hoisin sauce is gluten-free. The dish becomes completely gluten-free with these substitutions.

→ What sides pair well with this beef?

Jasmine rice, steamed broccoli, or sautéed vegetables complement the rich flavors perfectly. The sauce also works well drizzled over noodles.

→ Can I make this ahead of time?

Absolutely! The beef actually tastes better the next day as flavors continue to meld. Reheat gently before serving.