Preheat oven to 450°F. Line a large sheet pan with parchment paper or lightly grease.
In a large bowl, combine steak strips, sliced peppers, and onions. Drizzle with olive oil and lime juice.
In a small bowl, mix together chili powder, cumin, garlic powder, salt, and pepper. Sprinkle over the steak and vegetables, tossing to coat evenly.
Spread everything in a single layer on the prepared sheet pan, making sure not to overcrowd.
Bake for 15-20 minutes, stirring halfway through, until steak is cooked to desired doneness and vegetables are tender with slightly charred edges.
Serve immediately with warm tortillas, sour cream, guacamole, and your favorite fajita toppings.