Colour the hot dog slices in oil then add the butter. Allow to melt then add flour and stir until foaming. Slowly pour in the milk and stir vigorously until thick, then bring to the boil and add the cheese.
Spoon the mixture into your onion rings and freeze.
When fully frozen, bread the onion rings by dipping them in a bowl of flour, followed by egg wash, followed by bread crumbs. Fry at 170°c/380°F for roughly 3 minutes.