Butterfly the chicken breasts to create a pocket and season with salt and pepper. Dredge lightly in flour.

Heat olive oil in a skillet and sauté minced garlic until fragrant, about 30 seconds.

Add fresh spinach to the skillet and cook until wilted, about 2-3 minutes. Mix in roasted red peppers and cook for an additional minute.

Stuff each chicken pocket with mozzarella cheese, then fill with the spinach and pepper mixture. Fold and secure with toothpicks if needed.

In the same skillet, heat olive oil and butter. Cook the stuffed chicken for 5-6 minutes on each side until browned and cooked through.

Let the chicken rest for 5 minutes, then slice and serve warm.