Boil 3 qts water in a large pot. In a large skillet, heat 2 tbsp sesame oil over medium-high heat. Add beef and cook until brown. Remove cooked meat from pan and set aside in a large bowl.
Saute carrots in same pan as beef, stirring frequently until tender, about 5 minutes. Remove carrots and add to bowl with the meat. Saute scallions in same pan until wilted, then remove and set aside with carrots and meat. Add sesame oil as needed. Saute onions until slightly brown, then add to bowl. Saute spinach until fully cooked. Add to bowl.
Place glass noodles in boiling water. Turn off heat, and let soak for 5 minutes. As noodles are cooking, stir-fry mushrooms with minced garlic until cooked, then remove and add to bowl with meat, carrots, scallions, etc. Drain noodles.
In large pan, mix noodles and soy sauce and cook over medium heat for 5 minutes. Add noodles to bowl and mix with cooked ingredients.