Normally an outside-summer-BBQ thing, doing this indoors is fine if you use a cast iron pan. I don't think anything else will quite do it right, but hey, I can't stop you. Better open a window, though. If you use the proper amount of high heat, there will be smoke happening.
1/2 cup olive oil
1/3 cup soy sauce
2 large cloves garlic
1/4 cup lime juice
1 teaspoon red pepper flakes
1 teaspoon ground cumin
2 tablespoons dark brown sugar
2 pounds inside skirt steak (or any thin, lean steak)
Heat cast iron pan, hot. Blow the dust off the blender and put in oil, soy sauce, garlic, lime juice, red pepper, cumin, and sugar and puree.
Put the steak on a cutting board and pound it flat. Cut into reasonable pieces if need be (don't want to overcrowd your pan).
In a large heavy duty, zip top bag, put pieces of skirt steak and pour in marinade. Seal bag, removing as much air as possible. Allow steak to marinate for 1 hour in refrigerator.
Remove steak from bag and pat dry with paper towels. Add steak to hot pan. Turn when dark and crusty (mmm...). When finished cooking, place meat in double thickness of aluminum foil, wrap, and allow to sit for 15 minutes.
Meanwhile, saute the vegetables in the same hot pan, getting them a little blackened but not overly softened.
Remove meat from foil, reserving foil and juices. Slice thinly across the grain of the meat. Return to foil pouch and toss with juice. Combine back with the vegetables in the hot pan, turn off heat and serve with tortilla wraps and sour cream, and guacamole if you have it. Cheese optional.