Preheat and prep: Heat your oven to 375°F (190°C).
Lightly grease a 9x13-inch baking dish.
Sauté the garlic: In a small skillet, warm 1 tablespoon olive oil over medium heat. Add the minced garlic and cook 30–60 seconds until fragrant. Don’t brown it.
Mix the base: In the baking dish, stir together the uncooked rice, chicken broth, marinara sauce, sautéed garlic, Italian seasoning, red pepper flakes, and a pinch of salt and pepper.
Add the chicken: Fold in the cooked chicken, distributing it evenly so every scoop gets some.
First bake: Cover the dish tightly with foil.
Bake for 35–40 minutes, until the rice is mostly tender and liquid is nearly absorbed. Give it a quick stir.
Top with cheeses: Sprinkle mozzarella and half the Parmesan evenly on top.
Make the crunchy topping: In a small bowl, mix panko with the remaining 1 tablespoon olive oil and the rest of the Parmesan. Scatter over the cheese layer.
Final bake: Return to the oven, uncovered, for 10–15 minutes.
The top should be golden and the casserole bubbly around the edges.
Rest and garnish: Let it sit 5–10 minutes so the rice settles. Finish with chopped basil or parsley, and add a few extra grinds of black pepper.
Serve: Spoon into bowls or plates. It pairs nicely with a crisp green salad or steamed broccoli.