Heat oil in a large deep-fryer or heavy pot over high heat to 365 degrees. Test to make sure it is hot before adding potatoes. When oil is hot, slowly add potato slices, separating them with a long handled, heatproof spoon, and fry for 2 minutes. Lower heat to medium and fry 3 minutes more, stirring to keep slices separate and frying evenly. Use a slotted spoon to scoop up potatoes into a wire-mesh strainer. Shake excess oil back into deep fryer, then spread potato slices on a
baking sheet and let cool 10 minutes.
If you are also frying fish, prepare it now.
Make sure oil is hot. Add potatoes and fry for 1 minute. Reduce heat to medium and continue to fry potatoes until crisp and golden brown, about 6 minutes more. Remove potatoes with a slotted spoon and drain on paper towels. Serve immediately, sprinkled with vinegar and salt.
Yield: 6 cups/4 servings