Preheat the oven to 425 degrees.

Prepare a sheet pan with parchment paper. (Aluminum foil or the sheet pan itself also works. Just be sure to spray with non-stick spray.)

In a small bowl, mix everything for the homemade fajita seasoning. Set aside.

Thinly slice the chicken thighs into fajita size slices. Season with salt and pepper. Then add HALF of the fajita seasoning, coating all of the chicken well. Place the chicken on one side of the sheet pan.

Thinly slice all 3 bell peppers and the onion. Place each in a row on the sheet pan. Drizzle the vegetables with olive oil and coat them with the remaining fajita seasoning.

Now mix everything together, the chicken and vegetables.

Bake for 20 minutes.

Remove from the oven and enjoy on flour tortillas! You can add the juice of 1 lime and sprinkle it with fresh cilantro for some extra flavor.