Cook glass noodles according to package directions until fully tender. Drain and set aside.
Heat neutral oil in a pan over medium-high. Cook beef with garlic until just done. Remove and set aside.
In the same pan, sauté onion, carrot, and mushrooms until softened.
Add cooked noodles, beef, soy sauce, sugar, and black pepper. Toss gently until glossy.
Add baby spinach and sesame seeds. Toss once more and serve immediately.