Heat a couple of inches of oil in a deep pot over medium to medium-high heat. The oil, 6 cups or so, will take 10 minutes or so to heat evenly. To test, a piece of bread dropped into oil should brown in a count of 20 or bubbles should form on the handle of a wooden spoon inserted into oil.
Separate and toss the rings in buttermilk. Cover a large, deep plate with plastic wrap for easy-clean up. Combine flour, cornmeal, spices, and salt on the plate. Toss 1/3 of the rings in the breading at a time and coat evenly. Fry 3 to 4 minutes until deep golden. Drain on a paper towel lined plate. Repeat.
Combine the sour cream with peppers and dill in food processor and process until a smooth sauce forms. Transfer to a dish for dipping. Surround with O rings and serve.