Heat 1 tablespoon olive oil in a large skillet over medium-high heat. Add in the diced 1/2 small white onion, 1 large red bell pepper, and the diced 2 large white or cremini mushrooms. Sauté until vegetables are tender, about 5 to 7 minutes. Add minced 1 clove garlic in during the last 1 minute of cooking. Remove from pan into a small bowl and set aside.
Pound out 4 large boneless skinless chicken breasts until thin, or butterfly breasts. Spoon vegetable mixture into the middle. Sprinkle with 1 cup shredded pepper jack cheese. Fold chicken breasts over so filling is inside. Secure with toothpicks if desired.
In a small bowl combine 1 teaspoon ground cumin, 1 teaspoon chili powder, 1 teaspoon onion powder, 1 teaspoon salt, and 1/2 teaspoon crushed red pepper flakes(if using). Sprinkle over chicken breasts.
Wipe out the skillet you used for the vegetables and return to medium-high heat. Add remaining 1 tablespoon olive oil to the pan along with 1 tablespoon salted butter. Add in chicken breasts and cook for 8-10 minutes per side, or until chicken reaches an internal temperature of 165 degrees Fahrenheit.
Drizzle with 2 tablespoons lime juice before serving and garnish with freshly chopped 2 tablespoons chopped fresh cilantro (optional).
Video
Notes
BAKING INSTRUCTIONS: Instead of cooking the stuffed chicken in a skillet on the stovetop, you can also cook it in the oven instead. Place the stuffed chicken into a lightly greased 9x13 pan. Bake in a 400 degree oven for about 30 minutes, until chicken reaches an internal temperature of 165 degrees.