Preheat the oven to 450 degrees, and line a baking sheet with parchment paper.
Slice the peppers and onion into thin strips and lay them onto the baking sheet along with the chickpeas.
Drizzle on the olive oil and then sprinkle on chili powder, garlic powder, cumin and salt. With your hands gently toss it all together to combine and coat the vegetables well, and then spread it all out in an even layer.
Put the tray in the oven and roast for 10 minutes. Remove the tray and flip the vegetables. Then roast for another ten minutes.
Serve the fajita vegetables with warmed corn tortillas and garnish with fresh cilantro and hot sauce if desired.