Pound chicken breasts to 1 inch thick. Cut a pocket down the middle of each without cutting all the way through. Sprinkle with 1/4 teaspoon salt and 1/8 teaspoon pepper.
Combine cream cheese, Greek yogurt, mozzarella, artichoke hearts, drained spinach, remaining 1/4 teaspoon salt and remaining 1/8 teaspoon pepper.
Fill each chicken breast with equal amounts of spinach-artichoke filling. Reserve any extra filling.
Heat olive oil in a large skillet over medium. Add stuffed chicken breasts, cover and cook 7-8 minutes per side, or until chicken reaches 165°F.
During the last few minutes, add any reserved filling to the skillet to heat through. Serve with cauliflower rice, rice, mashed cauliflower or mashed potatoes.