This oven baked 3-ingredient chicken Florentine casserole is the kind of simple comfort food that earns a permanent place in a family recipe box. With tender chicken, creamy spinach, and a golden baked topping, it has that dependable church-supper warmth that made so many midcentury casseroles beloved, and it is especially handy on busy days when you want something hearty without a long ingredient list.
Serve this casserole with buttered egg noodles, fluffy rice, mashed potatoes, or a slice of warm bread to catch every bit of the creamy sauce. For a lighter plate, add a simple green salad, steamed green beans, or roasted carrots, and if you are feeding a crowd after a gathering, a fruit salad or gelatin salad on the side gives it that classic Sunday-dinner feel.
Oven Baked 3-Ingredient Chicken Florentine Casserole
Servings: 6
Ingredients
2 pounds boneless, skinless chicken breasts or chicken tenders
1 package (10 to 12 ounces) frozen creamed spinach, thawed
1 1/2 cups shredded mozzarella cheese
Directions
1. Preheat the oven to 375°F and lightly grease a 9x13-inch baking dish or similar casserole dish.
2. Arrange the chicken in an even layer in the prepared baking dish. If the chicken breasts are very thick, slice them in half horizontally or pound them slightly so they cook evenly.
3. Spoon the thawed creamed spinach evenly over the chicken, spreading it gently so the pieces are mostly covered.
4. Sprinkle the mozzarella cheese evenly over the top.
5. Bake uncovered for 35 to 45 minutes, or until the chicken is fully cooked and the casserole is hot and bubbly with a lightly golden top. If you like a deeper golden finish, broil for 1 to 2 minutes at the end while watching closely.
6. Let the casserole rest for 5 minutes before serving so the sauce settles a bit, then spoon onto plates and serve warm.
Variations & Tips
Kid-Friendly Version: If your family is cautious about spinach, chop the spinach a little more after thawing so it blends smoothly into the sauce. A mild mozzarella topping keeps the flavor gentle and familiar.
Extra Cheesy: Use a mix of mozzarella and Monterey Jack for a richer topping. This is a nice way to make it feel a little more special for a potluck or Sunday supper.
Use Chicken Thighs: Boneless, skinless chicken thighs work beautifully here and stay especially juicy. Just be sure they are arranged in a single layer and cooked through before serving.
Make-Ahead Tip: Assemble the casserole a few hours ahead, cover, and refrigerate. When ready to bake, let it sit at room temperature for about 20 minutes first so the dish goes into the oven without a big temperature shock.
Helpful Cooking Tip: Because ingredient brands vary, check the chicken with a meat thermometer and make sure the thickest part reaches 165°F. If the top browns before the chicken is done, loosely tent the dish with foil for the rest of the baking time.