Preheat oven to 375. In a 12 inch cast iron skillet over medium heat, add oil. Once oil is hot add ground beef to the pan, breaking it up as it cooks. When ground beef is cooked, add in onions, garlic, and peppers. Cook for about two minutes or until fragrant and translucent. Add in seasoning mix, stir until combined. Then pour in chili beans, rotel, and bloody mary mix. Stir together and continue to simmer for another 5 minutes
Mix together corn muffin mix, milk and eggs until just combined. Remove chili from heat and sprinkle shredded cheese on top. Then spread corn muffin batter evenly over the top of the chili & cheese. Place in oven and bake for 30 - 35 minutes or until cornbread is cooked through. I find that the cornbread top starts to brown early, well before it is finished cooking, if this happens place a piece of aluminum foil sprayed with cooking oil over the top. Also be sure to put a baking sheet on the oven shelf below just in case of any bubbling over spills. The cast iron skillet will get full as it bakes
Remove from oven, let set for about 10 - 15 minutes, and enjoy. Serve with sour cream, chives, and shredded cheese