Place the steak, shrimp, peppers, onion, garlic and lemon/lime on a large sheet pan.
Drizzle with the olive oil and season with fajita spices, salt and pepper. Toss everything together until well coated in the spice mixture.
Bake for 10-12 minutes until the steak is tender and the shrimp are pink. (**see note)
Remove from the oven, slice the steak into thin strips then squeeze the lemon/lime wedges over everything before enjoying with warmed tortillas and fresh cilantro.
Notes
*If you don't have a pre-blended fajita seasoning on hand, you can make your own by combining: 2 teaspoons cumin, 2 teaspoons chili powder, 1 teaspoon coriander.**Cooking time will depend on the thickness of your steak and how you like it cooked. For thin sirloin steaks as shown, 10 minutes will be cooked to about a medium temperature. If you only have a thicker steak, either slice into thinner strips before baking or, bake it without the shrimp for 10 minutes then add the shrimp to the pan so they don't overcook.