Step 1
Preheat the oven to 400 degrees. Cover a sheet pan with aluminum foil for easy cleanup. Mix together the chili powder, garlic powder, paprika, cumin, kosher salt, oregano, and black pepper to create your fajita spice blend.
Step 2
Add the sliced steak, bell peppers, and red onion to a ziploc bag or bowl. Add the juice of 1 lime, half the olive oil, and a little more than half of the fajita seasoning. Toss to coat and let marinate for 15 minutes.
Step 4
When ready to cook, lightly spray the foil with cooking spray. Add the shrimp, peppers, and onions in a single layer. Cook for 6 minutes (for medium rare at the end of cooking). Cook for about 8 minutes for medium.
Step 5
Carefully remove the sheet pan and add the shrimp. Make sure everything is in a single layer. Return to the oven for 4-6 minutes until shrimp is cooked through and steak is cooked to your liking.