Preheat your oven to 350°F.
Drizzle olive oil over chicken breasts and place them on a sheet pan.
Roast in the oven until cooked through.
While the chicken is roasting, add olive oil to a large pot over medium heat.
Throw in the onions and garlic, cooking until the onions are translucent.
Add red bell peppers, red pepper flakes, and chili powder, stirring to combine the flavors.
Pour in the canned tomatoes and chicken stock.
Let it simmer.
Once the chicken is done, let it cool slightly.
Remove the skin and bones, then shred the meat into bite-sized pieces.
Add it to the pot.
Let the chili simmer on low heat for at least 20 to 30 minutes.