PREHEAT the oven to 400°.
COMBINE the peppers, onions, sliced flank steak, olive oil, chili powder, cumin and salt in a large bowl until is completely mixed together and set aside.
UNFOLD a Reynolds Kitchens® Oven Bag and open it up at the seal and add 1 tablespoon of flour. Close the bag and shake.
PLACE the bag into a 13 by 9 casserole dish and pour the fajita mixture into the bag.
CLOSE up the bag with the tie that’s provided and using a pair of scissors make 6 half inch slits in the top of the bag.
TUCK the extra plastic from the bag into the casserole dish.
BAKE in the oven on 400° for 40 minutes or until the meat is browned, cooked throughout andreaches an internal temperature of 165°.
CUT along the top of the bag and open it up once it’s finished cooking and drain any excess liquid from the bag.
Serve the fajitas alongside fresh cilantro, lime slices and tortillas