Preheat the oven to 350°F. Wash the chicken and pat dry. Using a sharp knife, cut a slit halfway through chicken breast to create a cavity for the stuffing.

Heat 1 TBSP of olive oil in a large ovenproof skillet over medium-high heat. Once the oil is hot, add the spinach and saute until wilted but still bright green, about 2-3 minutes. Remove from the heat and roughly chop once cool.

In a bowl, mix the chopped spinach, pine nuts, and feta. Add more pine nuts or feta to taste.

Sprinkle the chicken breast all over with salt and pepper. Dust the outside of the chicken with flout. Stuff the chicken cavity with the spinach mixture.

Heath the remaining TBSP of olive oil over medium-high heat in same skillet. Cook the chicken breasts until browned on both sides, about 3-4 minutes per side.

Place the skillet in the oven and bake until the chicken breast is cooked through, about 20 minutes. Remove from oven and let the chicken rest for 5 minutes before eating.