Preheat oven to 400°F. Spray a large baking pan with non-stick cooking spray or foil and set aside. You may need to use two depending on how large your tray is.
To make the seasoning, combine the chili powder, cumin, garlic powder, sea salt and black pepper in a small bowl. Set aside.
Add the sliced steak to a large gallon zip lock back. Drizzle with 1 tablespoons olive oil, juice from one lime and sprinkle with ⅔ of the fajita seasoning. Mix and shake the bag well until all the steak is coated. Let marinate in the fridge for 15 minutes or overnight.
Spread the sliced bell peppers and onion on the prepared baking sheet. Drizzle with 1 tablespoon of olive oil and then sprinkle with the remaining fajita seasoning. Toss to coat.
Roast the vegetables in the preheated oven for 15 minutes then remove from the oven and stir then push all the veggies to one side of the tray, trying to keep them in an even layer.
Add the marinated steak in an even layer to the tray and place back in the oven for 10-12 minutes or until steak has reached your desired doneness.
Wrap tortillas tightly in foil and warm in oven during the last 5 minutes of the fajitas cooking. I just stick them in the corner of the pan.
Drizzle lime juice evenly over the top of the pan and sprinkle with chopped cilantro.
Serve warm with tortillas tortillas and optional toppings.