Prepare the Chicken: Pat the chicken breasts dry with a paper towel. Place one breast on a cutting board and, with your hand flat on top, carefully slice horizontally into the thickest part to create a pocket. Be sure not to cut all the way through. Open it up like a book. Repeat with the remaining chicken breasts. Season the inside and outside of each breast with salt and pepper.

Make the Filling: In a medium bowl, combine the softened cream cheese, grated cheddar, crumbled bacon, finely chopped jalapeños, minced garlic, onion powder, and chopped chives. Mix everything together until it's well combined. I find using a fork works best to break up the cream cheese.

Stuff the Chicken: Divide the cheese mixture evenly among the four chicken breasts, spooning it into the pocket you created. Don't overfill it, as the filling will expand and leak out during cooking. Fold the top of the chicken breast over to close the pocket. You can secure it with a couple of cocktail sticks if you're worried about it opening up.

Sear the Chicken: Heat the olive oil in a large, oven-safe frying pan or skillet over a medium-high heat. Carefully place the stuffed chicken breasts in the hot pan. Sear for 4-5 minutes on the first side, without moving them, until they are beautifully golden brown.

Flip and Cook: Flip the chicken breasts over. Reduce the heat to medium-low, cover the pan with a lid, and continue to cook for another 10-15 minutes. The exact time will depend on the thickness of your chicken. The chicken is cooked when it's no longer pink in the middle and the juices run clear. For complete confidence, use a meat thermometer; it should read 74°C (165°F) at the thickest part of the meat, as recommended by the Food Standards Agency.

Rest Before Serving: Once cooked, remove the chicken from the pan and place it on a clean cutting board. Let it rest for 5-10 minutes. This crucial step allows the juices to redistribute throughout the meat, keeping it moist and tender. It also allows the cheesy filling to set up slightly. Serve whole or sliced.