Using a large knife, thinly slice steak crosswise into thin strips. Toss with chili powder, cumin and pepper.
In a non-stick skillet, heat half of the oil over medium high heat and brown beef. Remove to plate. Add remaining oil in same skillet and sauté onion, bell peppers and cilantro for 4 minutes or until tender crisp. Return beef to skillet and heat through.
For the lime sour cream, in a small bowl, stir together sour cream, lime zest and lime juice.
Divide beef-vegetable mixture among tortillas and top with lime sour cream.
Cut down on preparation time with a little planning. Slice vegetables and beef ahead of time, and make the lime sour cream. That way, you only need 10 minutes to make dinner.
Little chefs will be excited to help. Ask them to prepare the lime sour cream and assemble their fajitas.
Switch up the protein. Try tofu: add 5 mL (1 tsp) of oil to the spice mixture to help it stick to tofu. You can also use 2 boneless, skinless chicken breasts (about 580g/¼ lb).