Prep the oven and pan. Preheat your oven to 400°F (200°C). Set a large oven-safe skillet on the stove. If you don’t have one, you’ll sear in a skillet and transfer to a baking dish.

Flatten the chicken. Place each chicken breast between two pieces of plastic wrap or parchment. Pound gently with a meat mallet or rolling pin until about 1/2 inch thick. This helps it cook evenly and makes rolling easier.

Season the chicken. Sprinkle both sides with 1 teaspoon salt, 1/2 teaspoon black pepper, 1 teaspoon paprika, and 1/2 teaspoon onion powder. Set aside.

Cook the spinach. Add the fresh spinach to a dry skillet over medium heat and sauté 1–2 minutes until wilted. If using frozen spinach, thaw and squeeze out as much water as possible. Drain well so the filling isn’t watery.

Make the filling. In a bowl, mix wilted spinach, cream cheese, Greek yogurt, Parmesan, garlic, lemon zest, a pinch of salt and pepper, and red pepper flakes if using. Stir until smooth and evenly combined.

Fill and roll. Lay each chicken breast flat. Spoon about 2–3 tablespoons of filling down the center, leaving space at the edges. Roll up tightly from the short end, then secure with toothpicks. Alternatively, cut a pocket in the side of each breast and stuff the filling inside.

Sear for flavor. Heat 1–2 teaspoons olive oil in the skillet over medium-high heat. Add the chicken seam-side down. Sear 2–3 minutes per side until lightly browned.

Bake to finish. Transfer the skillet to the oven (or move chicken to a baking dish). Bake 12–16 minutes, or until the thickest part reaches 165°F (74°C).

Rest and slice. Let the chicken rest for 5 minutes to keep juices in. Remove toothpicks and slice into rounds, or serve whole with any pan juices spooned over.

Garnish and serve. Sprinkle with chopped parsley or basil and a squeeze of lemon. Pair with roasted vegetables, a light salad, or cauliflower rice.