Stem and seed the bell peppers, green chilies, and jalapenos (be sure to use rubber gloves). Mince jalapenos. Cut bell and green chilies into thin slivers (I used a food processor).
Cut the chicken crosswise into thin slices about 3 inches long.
Place a skillet over med high heat until fairly hot, add the oil. Add the chicken,black pepper and stir-fry until the chicken is opaque throughout, 4 or 5 minutes. Remove chicken to a serving dish. Return the pan to the heat, add the garlic and cumin, stir-fry for a minute, being careful not to let the garlic burn. Add the bell peppers and chilies. Stir-fry until they begin to wilt 2-10 minutes, I prefer the longer cooking time. Return chicken to the pan; add cilantro and salt to taste. Stir to mix evenly and transfer to a serving dish.
Serve with warm tortillas. To assemble a taco, fill a tortilla with chicken mixture, squeeze a lime wedge over the filling, and add a bit of sour cream. Enjoy.
Note: To warm tortillas, stack them on top of each other and wrap tightly in aluminum foil. Heat for 10 to 12 minutes in a 350 degree oven. Or wrap loosely in waxed paper and microwave; a stack of 6 tortillas will take 45 to 60 seconds at full power.