Step 1: Cook the Noodles

Bring a large pot of salted water to a boil and cook the noodles according to the package instructions until al dente. Drain and set aside. Toss with a bit of sesame oil to prevent sticking.

Step 2: Brown the Ground Beef

In a large skillet or wok, heat 1 tablespoon of vegetable oil over medium-high heat. Add the ground beef and season with a pinch of salt and pepper. Cook, breaking up the meat with a spatula, until browned and fully cooked, about 5-7 minutes. Drain any excess grease and set the beef aside.

Step 3: Sauté Garlic and Ginger

In the same skillet, heat the remaining tablespoon of vegetable oil over medium heat. Add the minced garlic and grated ginger. Sauté for 1-2 minutes until fragrant, being careful not to burn them.

Step 4: Make the Mongolian Sauce

Reduce the heat to low and add the soy sauce, brown sugar, hoisin sauce, oyster sauce (if using), sesame oil, and red pepper flakes to the skillet. Stir well to combine and bring the mixture to a gentle simmer.

Step 5: Thicken the Sauce

Add the cornstarch slurry (cornstarch mixed with water) to the skillet. Stir continuously for 1-2 minutes until the sauce thickens and coats the back of a spoon.

Step 6: Combine Beef and Sauce

Return the cooked ground beef to the skillet and toss to coat it evenly in the sauce. Let it simmer for 2-3 minutes to absorb the flavors.

Step 7: Add the Noodles

Add the cooked noodles to the skillet and toss everything together until the noodles are fully coated in the sauce. Taste and adjust the seasoning if needed.

Step 8: Garnish and Serve

Remove the skillet from heat and garnish with chopped green onions and sesame seeds. Serve hot and enjoy your Mongolian ground beef noodles immediately!