Preheat oven to 425°F.
In a mixing bowl, mash together cheese, garlic, pear, onion, salt, pepper and then stir chopped spinach leaves until combined.
Cut a slit 3/4 of the way through the chicken breast without cutting all the way through. This will make a pocket to put the stuffing in.
Stuff each chicken breast with 1/4 of the mixture and close it with a toothpick.
Lightly season the chicken breast with salt and pepper.
Heat cooking oil in an oven-proof pan over medium heat. Add chicken and cook until golden brown on each side (~4 minutes per side)
Bake at 425˚F for 10-15 minutes or until thermometer inserted into the thickest part of the chicken registers at 165˚F.
Let chicken rest for 5 minutes before slicing. Spoon pan juices over chicken and serve.
