Baked chicken and pastina

Chicken second courses

Baking

1 cup pastina pasta (or any small pasta) 2 tablespoons olive oil ½ cup cubed chicken breast (1-inch cubes) ½ cup diced onion (about ½ a small onion) 1 clove garlic, minced 1 (14.5-ounce) can diced tomatoes with juice 1 cup shredded mozzarella ¼ cup chopped fresh flat-leaf parsley ¼ teaspoon kosher salt ¼ teaspoon freshly ground black pepper ¼ cup bread crumbs ¼ cup grated Parmesan 1 tablespoon butter, plus more for buttering the baking dish