Remove the outer skins from the onions. Slice the onions into 1/4-inch-thick slices and separate into rings. Combine the buttermilk and 3 tablespoons salt in a large bowl. Put the flour in a second large bowl and the cracker meal in a third large bowl.
Working in handful-size batches, dip the onion rings in the buttermilk until all are moistened, then put in the bowl of flour and use your hands to dust with the flour to coat. Carefully shake off excess flour and then quickly dip the rings back in the buttermilk to moisten once again. Put the rings in the bowl of cracker meal and use your hands to dust with the meal to coat. Carefully shake off excess meal from each ring and transfer to a shallow pan or baking sheet. Repeat the process with the remaining rings so all are dipped and coated. Refrigerate the rings for at least 4 hours to set the coating (overnight is best).
Heat the oil in an electric deep fryer to 350 degrees F. Gently drop enough of the coated rings into the fryer basket so that it is two-thirds full. Lower the basket into the hot oil and cook the rings until lightly golden brown, about 2 1/2 minutes. Remove the basket and shake off the excess oil, or allow the basket to rest until the basket has stopped dripping. Turn the basket over or use tongs to remove the rings and place them on a large plate or serving tray. Repeat with the remaining onion rings. Salt to taste or allow each person to season individually. Serve with ketchup or ranch dressing for dipping, if desired. Best served warm.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.
Recipe courtesy of George The Chili King Drive-In, Des Moines, IA