In a large skillet over medium heat, add the sesame oil and sauté the onions until translucent, about 5 minutes.
Add the garlic and sauté for another minute until fragrant.
Add the ground beef to the skillet, cooking until browned, about 6-8 minutes. Drain any excess fat.
Stir in the mushrooms and cook until softened, about 4 minutes.
Add the soy sauce, oyster sauce, and black pepper. Mix well.
In a large mixing bowl, combine the cooked noodles, beef mixture, cream of mushroom soup, and half of the shredded cheddar cheese. Mix until evenly incorporated.
Pour the mixture into a greased 9×13 inch baking dish and spread it evenly.
Sprinkle the remaining cheddar cheese on top.
Bake in the preheated oven for 25-30 minutes, until bubbly and the cheese is golden brown.
Garnish with sliced green onions before serving.
Variations & Tips
For a vegetarian version, omit the ground beef and use a combination of tofu and extra mushrooms. For a bit of heat, add some red pepper flakes or a dash of hot sauce to the beef mixture. If you prefer a crunchier topping, consider adding crushed fried wonton strips or panko breadcrumbs on top before baking. You can also experiment with different cheeses or add some bean sprouts and snow peas for extra texture.
