Ingredients
Beef
- 1½ pounds flank steak or sirloin
- ¼ cup cornstarch
- ½ teaspoon salt
- ½ teaspoon black pepper
- 2 tablespoons neutral oil (vegetable or canola)
Sauce
- ½ cup low-sodium soy sauce
- ½ cup water
- ¾ cup brown sugar
- 3 cloves garlic, minced
- 1 tablespoon fresh ginger, minced or grated
- ½ teaspoon red pepper flakes (optional)
Vegetables
- 4 green onions, sliced into 2-inch pieces
Equipment Needed
- Large skillet or wok
- Mixing bowls
- Tongs or spatula
Step 1: Prepare the Beef
Slice the beef thinly against the grain. This is essential for tenderness.
Place the sliced beef in a bowl and toss with cornstarch, salt, and black pepper until evenly coated. Let it rest for 10 minutes. This coating helps create a crisp exterior and thickens the sauce later.
Step 2: Make the Sauce
In a bowl, whisk together soy sauce, water, brown sugar, garlic, ginger, and red pepper flakes if using. Set aside.
Step 3: Sear the Beef
Heat the oil in a large skillet or wok over medium-high heat.
Add the beef in a single layer, working in batches if needed. Cook for 1 to 2 minutes per side until browned and slightly crispy.
Remove the beef from the pan and set aside.
Step 4: Simmer the Sauce
Carefully pour the sauce mixture into the same skillet. Bring to a gentle boil, scraping up any browned bits from the bottom of the pan.
Let the sauce simmer for 3 to 5 minutes until slightly thickened.
Step 5: Combine
Return the beef to the skillet and toss to coat in the sauce.
Add the green onions and cook for another 1 to 2 minutes until slightly softened but still vibrant.
Step 6: Serve
Remove from heat and serve immediately.
Serve over steamed rice, fried rice, or noodles. Garnish with sesame seeds if desired.
Storage and Reheating
Store leftovers in an airtight container in the refrigerator for up to 3 days.
Reheat gently in a skillet over medium heat or in the microwave in short intervals.
Tips for Best Mongolian Beef
- Slice beef thin and against the grain
- Do not overcrowd the pan
- Brown sugar gives authentic sweetness
- Fresh ginger makes a big flavor difference
