Mireya's Stir-Fry

The second time I ever saw my now very close friend Mireya, she was making this for dinner and she had made so much that she kindly sent me home with enough marinated meat and cut up vegetables for me to feed my own family. It was so good, the kids said it was their favorite stir fry. So now it's called "Mireya's Stir Fry". (Ironically, she hasn't made it since then and asks me for the recipe, which she told me over the phone as I wrote it down.) She got this recipe from her mother-in-law.

Sirloin tri-tip (Costco) partly frozen to make it easy to slice in small strips
2-3 tbsp. soy sauce
2 tbsp. corn starch
2 tbsp. oil
about 1 tbsp. fresh ginger (optional)
freshly ground black pepper

Slice the meat and marinate it in soy sauce, corn starch, oil, ginger, and black pepper for at least half an hour.

Wash and cut a combination of vegetables into bite-sized pieces. She did:
Broccoli
Asparagus
Red pepper
mushrooms
carrots
onion
garlic
gingerroot (optional)

Mix up the sauce. This is my version because I like a lot of sauce:
1 c. chicken broth (hot water mixed with bouillon is fine)
1-2 tbsp. oyster sauce
3 tbsp. soy sauce
1/2 tsp. sugar
2 tbsp. corn starch
1 tsp. sesame oil

Stir fry the meat in some oil and cook until barely done. Remove from pan and set aside. Stir fry the vegetables in some oil in order starting with the ones that take the longest time to cook. I start with carrots and onions. When vegetables are just about done, add the meat, then the sauce, and cook a few minutes until the sauce is thickened. Serve over rice.