Feta and Bacon Stuffed Chicken with Onion Mashed Potatoes

Preheat the oven to 350 degrees F (175 degrees C).

Place bacon in a large, deep skillet and cook over medium-high heat, turning occasionally, until evenly browned but still soft, 5 to 7 minutes. Cool bacon on a paper towel-lined plate; reserve grease in the skillet.

Mix together cooled bacon with feta cheese, 3 tablespoons sour cream, oregano, and black pepper in a small bowl until well combined; set aside.

Lay chicken breasts flat on a clean work surface. Use the tip of a sharp boning or paring knife to cut a 2-inch pocket in each chicken breast. Spoon bacon mixture into the pockets.

Place flour, bread crumbs, and beaten eggs into separate, shallow dishes. Dredge a chicken breast in flour; shake off excess. Dip into beaten eggs. Lift up so excess egg drips back into the dish. Press into bread crumbs to coat both sides. Repeat with remaining chicken breasts.

Reheat grease in the skillet over medium heat. Sear chicken breasts in the hot grease until browned on both sides, about 2 minutes per side. Reserve grease in the skillet. Transfer chicken breasts to a baking dish.

Bake in the preheated oven until chicken is no longer pink and filling is hot, 20 to 25 minutes. An instant-read thermometer inserted into the center should read at least 165 degrees F (74 degrees C).

Meanwhile, place potatoes into a large pot and cover with salted water. Bring to a boil. Reduce heat to medium-low, cover, and simmer until tender, about 20 minutes. Drain.

While potatoes are cooking, cook and stir onion in remaining grease in the skillet over medium heat until very tender and golden brown, about 10 minutes.

Place cooked potatoes into a large bowl. Add onion, remaining 3 tablespoons sour cream, and butter; mix well. Serve alongside stuffed chicken breasts.