Pour about 1 inch of oil into a heavy pot. Heat it to 350°F (175°C). No thermometer? Drop a flour flake in; if it sizzles immediately, you’re in business. If it smokes, you’ve gone too far—turn down the heat, buddy.
Carefully drop a small handful of the flour-coated rings into the hot oil. Don’t crowd them! They need personal space to crisp up. Fry for about 2 to 3 minutes, stirring gently, until they turn a deep golden brown.
Use a slotted spoon to scoop them out onto a plate lined with paper towels. Sprinkle immediately with a little more salt while they’re still hot. This is the crucial “flavor window.”