First, whip together the package of jiffy cornbread with the milk and eggs according to the package then sat the batter to the side. Preheat the oven to 350F.
In a pan on medium high heat brown the ground beef. When everything is almost browned toss in the Rotel tomatoes and the diced onion. Continue to cook until onions are fragrant.
Then, add in tomato sauce, corn and beans. Next, the taco and ranch seasoning packs. Mix everything very well and remove from heat. You can taste for seasoning but the tomato sauce still may have a metallic flavor since you haven't placed it in the oven yet.
Next, in a 16x9 baking dish add the hamburger mix in first then spread it out in an even layer. Now, carefully top the baking dish with the jiffy batter and spread it out evenly.
Place the baking dish in a preheated oven for about an hour. Do the first check at 45 minutes. You're looking for the cornbread to be fully cooked, a toothpick test is best right through the center.
Once done remove from oven and allow the cowboy cornbread casserole to cool a bit before serving. Enjoy.