Preheat the oven. Set it to 400°F (200°C).
Lightly grease a 9x13-inch baking dish with olive oil or nonstick spray.
Prep the chicken. Pat the chicken dry and cut into bite-size pieces. This helps it cook evenly and absorb the sauce.
Make the protein sauce. In a bowl, stir together Greek yogurt, 1/2 cup Parmesan, mozzarella, garlic, olive oil, Dijon, Italian seasoning, smoked paprika, onion powder, salt, pepper, and chicken broth. The mixture should be thick but spreadable.
Add the greens. Fold in the chopped spinach.
It will wilt in the oven and add color, fiber, and nutrients.
Combine in the dish. Add the chicken to the baking dish and pour the sauce over it. Toss to coat so every piece is covered. Spread into an even layer.
Top and bake. Sprinkle the remaining 2 tablespoons Parmesan over the top.
Bake uncovered for 22–28 minutes, until the chicken reaches 165°F (74°C) in the thickest pieces and the edges bubble.
Finish under the broiler. For a golden crust, broil on high for 1–3 minutes. Watch closely so it doesn’t burn.
Rest, garnish, and serve. Let it rest 5 minutes so the sauce sets. Sprinkle with parsley and serve with lemon wedges.
Pair with steamed veggies, roasted potatoes, zucchini noodles, or brown rice.