My son called me at the last minute coming back home from playing an early golf game. He was starving and was bringing a friend. I had not been grocery shopping yet so this was my "just a pinch" recipe I created.
1Preheat oven to 350
Line a shallow baking dish with aluminum foil and add 1/2 the onion sliced thin, sliced green and red pepper, BBQ sauce and salt and pepper to taste. Cover tightly with foil place in the oven. Place buttermilk in a bowl, add 3/4 teaspoon of the cajun seasoning and remaining sliced onion. Place in fridge for 10 minutes. Pour flour into large freezer bag with remaining cajun seasoning and salt/pepper.
Place canola/olive oil in medium fry pay and heat on med high heat. Remove onions soaking in buttermilk from fridge and place a litte at a time in freezer bag with flour. shake to coat. Place in frying pan until golden brown. Place on dish lined with napkin to remove extra oil. Open hoagie buns lightly coat both sides with mayo (mustard if desire) Remove beef from oven, divide into four portions place on hoagie buns and place buns back into the oven or 1-2 min. Remove from oven place onions on top and drizzle ranch dressing on top.