Step 1: Preheat your oven to 375°F (190°C).
Step 2: In a medium saucepan, combine 1 cup of uncooked quinoa with 2 cups of chicken broth. Bring to a boil, then reduce to low, cover, and simmer for about 15 minutes or until fluffy.
Step 3: In a large mixing bowl, combine the cooked quinoa, diced chicken, crushed tomatoes, tomato paste, balsamic vinegar, half and half, salt, pepper, and optional crushed red pepper. Mix until well combined.
Step 4: Transfer the mixture into a large casserole dish and spread evenly.
Step 5: Sprinkle half of the mozzarella cheese over the top, then add the halved grape tomatoes. Finish with the remaining mozzarella and grated Parmesan.
Step 6: Cover with foil and bake for 25 minutes. Remove the foil and bake for an additional 10-15 minutes until bubbly and golden.
Step 7: Let cool for a few minutes and garnish with chopped fresh basil before serving.