Heat the oven to 400°F and grease a 10-inch oven-safe skillet or 2 1/2-quart baking dish.
Combine the cooked chicken, pinto beans, corn, barbecue sauce and broth in the skillet and heat until bubbling.
Whisk the cornmeal, flour, baking powder and salt in a bowl.
Whisk the milk, egg and melted butter separately, then fold the wet mixture into the dry mixture just until combined.
Spoon the batter over the hot chicken filling and spread it gently to the edges.
Bake until the cornbread is golden and a pick inserted into the topping comes out clean, 22 to 26 minutes.