Not trying to do any fusion cooking, this just makes the most sense for what to call it - though it wouldn't pass for either teriyaki or fajitas.
You could have this without the teriyaki sauce or the sour cream. You could substitute sausage for the beef, and have sausage with green peppers and onions. In fact, a lot of things taste good in a pan-toasted tortilla. Nice change from a bread sandwich.
In a large skillet, pan toast a flour tortilla, either dry or with a little oil in the pan.
After removing the tortilla, saute (with a little oil)
Sliced green peppers
When nearly done add
Thinly sliced beef of your choice
Saute briefly and add
A little brandy (I use apricot), or port, maybe 1 Tablespoon
Soy sauce (maybe 1-2 Tablespoons)
Sugar (maybe 1-2 Tablespoons)
Grated fresh ginger (maybe 1/2 teaspoon)
Minced fresh garlic (1/2 clove, or 1/8 teaspoon dry)
A little hot pepper, or dried hot pepper flakes
Cook til the sauce reduces and coats the meat and veggies with a sweet, salty, syrup
Place in the toasted flour tortilla, and top with sour cream
Fold and enjoy.
optional: Serve the beef and vegetables on a green salad, with homemade croutons.
After you make this once you'll know how you want to adjust the sauce. You could use orange juice concentrate instead of the brandy, or perhaps apricot jam for the brandy and some of the sugar.
You could marinate the beef in the sauce, which is ordinarily how teriyaki is made.
I used bottom round roast, which is a tough cut of meat if not sliced thinly, and this is also why I'm careful not to overcook it. Skirt steak would work well here, as it does for fajitas. I've used london broil.