I grab a recipe off the internet for teriyaki sauce, then add some mirin, rice wine vinegar, and a tablespoon of garlic along with 3 tablespoons of corn starch, and then I pour it into a tupperware bowl, completely submerging sliced strips of steak in it, then I leave it in the fridge for 2-3 days. the meat looks unappetizing after it comes out of the fridge.
I cook the meat in a cast iron pan until the inside is almost fully cooked, then add vegetables like whole snow peas, thin grated carrot, and white or yellow onion. make sure the meat is fully cooked, and then serve it over rice.