Stir frying is the magic method of Asian cooking. The process involves high heat and constant sauteing. If you have a teflon wok, the high heat will ruin the teflon coating. To have a successful experience, all ingredients used must be cut in uniformed small pieces to ensure even distribution of heat. To have pieces cut in all types of pieces will create some that will be overcooked, some under cooked, just not good.
In stir frying you'll need to have some aromatics like garlic and ginger. I recommend using fresh garlic cloves. I personally dislike the minced garlic in a bottle with water, to me its not the same. Fresh garlic is good for you. Take the garlic, lay it on the chopping board and with the flat side of the cleaver, just smash the clove. Then take a piece of fresh ginger. Ginger has all sorts of good benefits for you. Peel off skin and smash it like you did with garlic.
Heat the wok on high, then add oil (2 tablespoon), vegetable or canola oil, add garlic and ginger but don't let it burn, stir constantly, then add meat and saute. Keep mixture moving, using a spatula. If you leave the mixture without moving it with high heat, then the mixture will burn. Add veggies are added last. Why? Veggies cook faster and you want the texture to be crispy. Color is a clear indicator. You want bright colors like emerald color green, bright orange for carrots,
While mixture is cooking, create a cornstarch solution (corn starch (1 teaspoon), water to make a slurry solution, add soy sauce, a dash of sugar, sesame oil or shao shing wine, and mix in. The cornstarch will thicken, and the flavors will enhance the flavor.