Preheat oven to 400 F.
Cut bell peppers (3) in half and de-seed.
Place peppers on a baking sheet and spray each side with cooking oil.
Place chicken breast (1 Lb) on a 2nd rimmed baking sheet.
Rub chicken with oil ( 1 tablespoon), and sprinkle with salt (1 teaspoon) and pepper (1/2 teaspoon).
Place both baking sheets in the oven, and bake for 25 minutes.
Meanwhile, add oil (1 tablespoon) to a large nonstick pan.
Once shimmering, add diced yellow onion (1) and saute until translucent (about 10 minutes).
Add minced garlic (2 cloves) and fresh spinach (10 Ounces) and cook until spinach has released its liquid and fully wilts.
Remove both baking sheets from the oven -- you'll know the bell peppers are done when they've softened, and the chicken is done once it's no longer pink in the center.
Allow the chicken to cool, then shred.
Add cooked veggies and shredded chicken to a large bowl.
In a small bowl, combine remaining oil (1 tablespoon), fresh lime juice (2 tablespoons), sour cream (1 cup), minced chipotle peppers (3 whole), oregano (1 teaspoon), cumin (1 teaspoon), chili powder (2 teaspoons), salt (1 teaspoon) and pepper (1/2 teaspoon).
Pour the ingredients from the small bowl over the chicken and veggies and stir to combine.
Spoon the filling into the bell peppers.
Sprinkle with shredded cheese.
Bake in the oven for 10 minutes, or until the cheese has melted.
Serve with cilantro and enjoy!