Trim fat from steak.
Slice steak diagonally across grain into thin strips.
Combine steak and next 7 ingredients (steak through ground red pepper) in a zip-lock plastic bag; seal bag, and shake well to coat.
Heat the tortillas according to package directions.
Heat 1 teaspoon oil in a large nonstick skillet over medium-high heat.
Add steak, onion, and bell peppers; sauté 6 minutes or until steak is done.
Remove from heat; stir in lime juice.
Divide mixture evenly among warm tortillas, and roll up.
Serve with sour cream.
Garnish with green salsa and cilantro sprigs, if desired.