Preheat oven to 425 degrees. Lightly spray an 8 x 8 inch baking dish
Place the sirloin into the prepared baking dish. Cut the sirloin into the desired size of pieces. Brush the oil over both sides of the sirloin
Sprinkle the sirloin with with 1/2 tsp of the dry thyme, 1 tsp of the salt, 1/2 tsp of the pepper. 1/2 tsp of the paprika, 1/4 tsp of the garlic powder, 1/4 tsp of the dry cilantro, and 1/4 tsp of the onion powder
Use a basting brush or fingers and press the seasonings into the sirloin. Turn the sirloin over and sprinkle the remaining seasonings over the sirloin. Press the remaining seasonings again into the sirloin.
Bake at 425 degrees for 20 - 30 minutes or until desired level of pink, or grill 5-7 minutes on each side or until desired level of pink. Serve immediately.