Heat 1 tablespoon of olive oil in an OVENPROOF large skillet over medium-high heat.
Combine the fennel seeds, garlic powder, oregano, sea salt, and freshly cracked pepper to taste in a small dish and mix well.
Sprinkle the spice dry rub evenly over both sides of the chicken.
Add chicken to the hot skillet and cook for 3 minutes or until browned. Turn the chicken over and place it in the oven for 20 minutes, or until cooked through.
Remove the chicken to a serving plate and cover with a foil tent.
Heat the remaining tablespoon of olive oil over medium-high heat in the same large skillet. Add bell peppers and onion; sauté for 3 minutes.
Stir in broth, scraping the pan to loosen browned bits. Reduce heat; simmer for 5 minutes.
Increase the heat to medium-high. Stir in vinegar, then season with sea salt and freshly cracked pepper to taste and cook for 3 minutes, stirring frequently.
Serve the bell pepper mixture and sauce over chicken. Enjoy!