Preheat your oven broiler to 500 F.
In a small bowl, combine all the ingredients for the fajita seasoning, and whisk until well combined.
2 tsp. chili powder, 1 tsp. paprika, ½ tsp. onion powder, ½ tsp. garlic powder, ¼ tsp. cayenne pepper, ½ tsp. ground cumin, Sea salt and freshly ground black pepper
Add the vegetables and steak to a bowl, season with the fajitas seasonings, drizzle with olive oil, and toss until well coated.
2 lbs. sirloin steak, 1 green bell pepper, 1 red bell pepper, 1 large onion, 2 tbsp. olive oil
Place the seasoned vegetables and steak on a baking sheet.
Broil in the oven for 5 to 6 minutes, turn the meat and vegetables once, and cook for another 5 to 6 minutes.
Serve with your choice of fresh salsa, lettuce leaves, or cauliflower tortillas.