In a large skillet or wok, heat the vegetable oil over medium-high heat. Add the ground beef and cook until browned, breaking it into small pieces as it cooks.

Once the beef is browned, add the minced garlic and grated ginger. Sauté for about 1 minute until fragrant.

In a separate bowl, whisk together the soy sauce, brown sugar, cornstarch, and water.

Pour the sauce over the cooked beef in the skillet. Stir well to combine and let it simmer for a couple of minutes until the sauce thickens.

Stir in the chopped green onions and sliced bell peppers.

Let the mixture simmer for another 3 to 5 minutes.

If using, drizzle sesame oil over the dish just before serving.

Serve the Mongolian Ground Beef over rice or noodles.