Preheat the oven to 375 degrees F (190 degrees C).
Heat oil in a skillet over medium-high heat. Add onion and a large pinch of salt. Saute until translucent, 3 to 5 minutes. Add bell pepper and poblano peppers. Season with black pepper, cumin, and oregano. Cook and stir until peppers start to soften, about 2 minutes. Add chipotles and adobo sauce. Stir to combine and remove from heat.
Add turkey and half the Cheddar cheese to the pepper mixture. Add enchilada sauce, remaining salt, and chicken broth. Stir mixture and pour it into a 9x12-inch baking dish; place dish over a sheet pan to catch drippings.
Whisk cornmeal, flour, sugar, and kosher salt together in a large bowl. Add eggs and milk; whisk into a thin batter. Ladle batter over the turkey mixture. Scatter remaining Cheddar cheese on top.
Bake in the preheated oven until the topping is browned and a toothpick comes out clean, 45 minutes to 1 hour.
