3 oz mozzarella cheese, sliced (low-moisture part-skim)
2 cloves garlic, freshly minced
1/2 teaspoon thyme leaves
2 cups fresh baby spinach
1 tablespoon olive oil
Instructions
Preheat oven to 200°C/390°F (or 180°C/356°F fan-forced). Cut a pocket into each chicken breast without cutting all the way through. Pat dry and season inside and outside with half the salt and pepper.
Melt butter in 10-12 inch oven-safe skillet over high heat. Add mushrooms and cook 3 minutes until golden. Add garlic, thyme, remaining salt and pepper. Cook 2 minutes. Add spinach and stir until wilted, about 30 seconds. Remove from heat.
Stuff mushroom mixture into chicken breast pockets. Top with cheese slices. Seal openings with 2-3 toothpicks.
Wipe skillet clean. Heat olive oil over medium-high heat. Sear stuffed chicken breasts 1.5 minutes per side until golden.
Transfer skillet to oven. Bake 15 minutes or until internal temperature reaches 74°C/165°F in the chicken flesh, avoiding the filling.
Remove toothpicks. Place on plate, cover loosely with foil. Rest 5-7 minutes before serving.
Notes
Cut pocket 3-4 inches wide on the side. Pat chicken completely dry before seasoning for best sear.
Use cremini or white button mushrooms. If skillet is smaller than 10 inches, cook mushrooms in batches.
Fresh mozzarella melts beautifully. Insert thermometer into thickest part from the side, avoiding cheese filling.
Store in airtight container up to 3 days refrigerated or 3 months frozen. Reheat at 175°C/350°F until 74°C/165°F.