Preheat your oven to 375°F (190°C).
Finely chop the fresh spinach and mince the garlic clove.
In a small mixing bowl, stir together the chopped spinach, minced garlic, Greek yogurt, and grated parmesan cheese until well combined.
Using a sharp knife, slice a pocket into the thickest part of the chicken breast, taking care not to cut all the way through to the other side.
Carefully spoon the spinach and yogurt mixture into the chicken pocket and secure the opening with toothpicks if necessary.
Season both sides of the stuffed chicken breast with sea salt and black pepper.
Heat the olive oil in an oven-safe skillet over medium-high heat and sear the chicken for 3-4 minutes per side until a golden crust forms.
Transfer the skillet to the preheated oven and bake for 12-15 minutes, or until the internal temperature of the chicken reaches 165°F (74°C).
While the chicken is baking, steam the broccoli florets for 5-6 minutes until they are tender-crisp and bright green.
Remove the chicken from the oven, let it rest for 5 minutes, and serve alongside the steamed broccoli.