Preheat oven to 350°.
Place chopped onion, red bell peppers and vegetable oil in a large skillet on medium to medium high heat and cook for 5 or 6 minutes, then save in a large mixing bowl.
Use the same skillet to fully brown the ground beef, 6 to 8 minutes.
Add the corn, black beans and Rotel tomatoes to the meat to heat, 1 to 2 minutes, then place the meat mixture into the bowl with the vegetables.
Cook the pasta in boiling, salted water until just before it becomes al dente (according to package instructions), drain, and place in the mixing bowl.
Fold all the casserole ingredients together, taste and add salt and pepper. Add any other ingredients as desired now also.
Spray a 9 by 13-inch casserole dish with cooking spray then add a thin layer of the meat mixture to the bottom of the baking dish. Top this with a layer of grated cheese. Continue to add a layer of meat mix , topped with cheese until the casserole dish is full. Reserve about 2 ounces of the cheese to add when finishing the baking.
Cover the casserole with aluminum foil and place it in the oven for 35 minutes. If you have an instant read thermometer, the casserole temperature should be around 160°F.
Remove the casserole from the oven and take off the foil covering and add the remainder of the grated cheese. Place the casserole back in the oven for 10 to 15 minutes to allow for the cheese to melt. Serve hot out of the oven.