Preheat oven to 425

In a small bowl mix together the garlic powder, oregano, cumin, paprika, and salt. Set aside.

Chop bell peppers into ½ inch wide slices. Cut the onion into 6-8 wedges, similar to how you would cut an apple. Keep the onion pieces together. This helps maintain the crisp texture. 

Put the chopped veggies in a large mixing bowl.

Slice the raw chicken breast into ½ inch slices. Try to keep the slices thin but even so they cook at the same pace. 

Put the chicken slices with the chopped veggies in the large mixing bowl. 

Mix in the olive oil and then the prepared seasoning. Mix altogether until chicken, bell peppers and onion are evenly coated.

Spread evenly on a baking sheet and put in the oven for 20 minutes.

Fajitas are done when chicken is cooked through and veggies are tender yet crisp.

Serve immediately on warm tortillas