If beef isn't your best thing, use pork or chicken. This makes enough for three large servings.

2 small beef steaks (whatever kind - even cube steaks work well)
2 or 3 tbsp. worcestershire sauce
salt, ground black pepper, other seasonings of choice such as cayenne, cumin, etc.
2 or 3 tbsp. lime or lemon juice
1 large bell pepper (anaheims work well here too, for a little more kick)
1/2 large onion
8" flour tortillas (low carb/high fiber)
for garnish:
>> grated cheese
>> sour cream
>> salsa or picante sauce
>> avocado slices
>> diced tomato
>> etc., etc.

Cut steaks, pepper & onion into thin strips.
Combine wooster, seasonings & lime juice.
Marinate beef strips in wooster mixture at least 30 minutes.
Preheat large heavy skillet until almost smoking.
Drain beef strips & toss into hot skillet. Stir fry for a minute.
Add green pepper & onion to skillet & continue stir frying until veggies begin to soften.

Warm the tortillas and fill with meat/veggies mixture . . . add garnish of choice & enjoy!