Mississippi Tamale Pie

Name: Mississippi Tamale Pie
Ingredients: 1 cup yellow cornmeal; 1/2 cup masa; 1 teaspoon salt; 6 tablespoons unsalted butter, plus more as needed; 4 cups milk or buttermilk; 2 large eggs, lightly beaten; 2 tablespoons unsalted butter; 1 cup diced yellow onion; 2 tablespoons minced garlic; 1 red bell pepper, seeded and diced; 3 cups cooked shredded chicken and sauce from South-of-Something Pulled Chicken, recipe follows; 2 tablespoons chopped cilantro leaves, plus more for garnish; Zest and juice of 1 lime; 2 cups grated Cheddar; Sour cream, for garnish; 1 teaspoon ground coriander; 1 teaspoon smoked paprika; 1/2 teaspoon ground cumin; Kosher salt and freshly ground black pepper; Two 3 1/2- to 5-pound whole chickens (roaster size); Olive or vegetable oil, as needed; One 28-ounce can chopped tomatoes; 6 cloves garlic, chopped; 2 cups minced yellow onions