In a large PAN, heat 2 tbsp oil over high heat.
Stir-fry beef (keep the marinade for later) for about 1 minute until it changes color.
Take the beef out and set aside.
In the same PAN, add 2 tbsp oil. Stir-fry vegetables over medium heat for 5 minutes.
Add 1 tbsp soy sauce and sherry halfway.
Add 1 cup of water, the marinade, and salt to taste.
Cook over medium-low heat for about 5 minutes until the vegetables are just cooked.
Dissolve starch in 1 tbsp water. Add the slurry to the PAN. Mix well.
Stir in the noodles. Cook over low heat for 2 minutes.
Return the beef and cook for about 1 to 2 minutes until it's just cooked.
Sprinkle some Sichuan  spices on the plated meal (optional).