Preheat the oven to a toasty 375 degrees F (190 degrees C).
In a skillet over medium-high heat, warm the oil. Cook onions with a generous pinch of salt until translucent, about 3 to 5 minutes. Add bell pepper and poblano peppers, season with black pepper, cumin, and oregano. Stir and cook until peppers begin to soften, around 2 minutes. Mix in chipotles and adobo sauce, then remove from heat.
Combine the turkey and half of the Cheddar cheese with the pepper mixture. Mix in the enchilada sauce, remaining salt, and chicken broth. Stir everything together and transfer it into a 9x12-inch baking dish placed over a sheet pan to catch drippings.
In a large bowl, combine cornmeal, flour, sugar, and kosher salt. Mix in eggs and milk until a thin batter forms. Pour batter over the turkey mixture and sprinkle the remaining Cheddar cheese on top.
Bake in the oven until the topping is golden brown and a toothpick inserted comes out clean, about 45-60 minutes.