Prepare the Noodles: Begin by cooking 8 ounces of rice noodles according to the package instructions. Once they are al dente, drain them, rinse with cold water, and set aside.
Cook the Beef: In a large skillet, heat 1 tablespoon of sesame oil over medium-high heat. Add 1 pound of ground beef and cook until it’s browned and fully cooked, breaking it up with a spoon as it cooks. This should take about 5-7 minutes. Drain any excess fat if necessary.
Add Aromatics: Sauté Garlic and Ginger: Reduce the heat to medium. Add 8 minced cloves of garlic and 1 tablespoon of minced ginger to the skillet. Sauté for about 1-2 minutes until they become fragrant. Add ½ teaspoon of red pepper flakes and stir well.
Add to the skillet the ½ cup of low-sodium soy sauce, 2 tablespoons of brown sugar, red chili flakes, and ¼ cup of hoisin sauce. Stir to combine.
Thicken the Sauce: Dissolve 2 teaspoons of cornstarch into beef broth to create a slurry. Slowly add this slurry to the sauce mixture, stirring constantly to avoid lumps.
Add Sauce to Beef: Pour the beef broth slurry mixture into the skillet with the cooked beef. Stir well to coat the beef evenly. Continue to cook over medium heat, allowing the sauce to thicken and bubble, for about 2-3 minutes.
Mix with Noodles: Combine Noodles and Beef: Add the cooked rice noodles to the skillet. Toss everything together until the noodles are well-coated with the sauce and the beef is evenly distributed. Cook for an additional 2 minutes to heat through.
Finish and Garnish: Add Green Onions: Stir in ⅓ cup of diced green onions. Cook for another minute, allowing the flavors to meld.
Garnish: If desired, sprinkle 1 tablespoon of sesame seeds over the top for an extra crunch.
Serve: Plate and Enjoy: Serve the Mongolian Ground Beef and Noodles hot, garnished with additional green onions or sesame seeds if you like.