In small dish, combine chili powder, garlic powder, onion powder, oregano, paprika, cumin, salt and pepper, and stir together until well mixed.
Place uncooked steak strips into re-sealable plastic bag and add spice mixture. Seal bag and shake/turn until steak is coated with seasoning.
Pour oil into large skillet and bring to medium heat. Add seasoned steak strips and stir to coat steak with oil. Cook, stirring and flipping occasionally, about 5 minutes, or until steak strips are cooked to taste. Remove from heat.
Warm tortillas slightly in microwave then lay out to fill. Divide lettuce and steak between tortillas and top each with 1 tablespoon of guacamole. Sprinkle each taco with sprouts and slices of tomato and radish.