On a Japanese mandoline, slice the garlic as finely as possible; it should be translucent.
Heat 2 cups vegetable oil in a large, heavy Dutch oven to 250 degrees F. Add the sliced garlic and cook until golden brown. Remove with a slotted spoon and drain on paper towels.
Peel and devein the prawns, leaving the head and tail pieces intact. Heat 2 tablespoons vegetable oil in a large saute pan over high heat until oil is almost smoking. Season 6 prawns with salt and pepper and add to hot oil. Cook 1 minute on each side and then transfer to a paper towel to drain. Repeat until all prawns are cooked, adding more oil as needed.
Arrange prawns on a plate and drizzle with the Lemon Confit, using some of the oil. Sprinkle with garlic chips and chopped parsley.
Prepare the Lemon Confit a couple days in advance. Slice the lemons lengthwise and place in a stainless steel pot. Add all remaining ingredients, except olive oil, cover with cold water, and bring to a boil over medium heat. Reduce heat to maintain a slow simmer; too much heat will cause the lemon to fall apart. Simmer for 15 minutes and then pour into sanitized mason jars. Seal and let cool in refrigerator.
When ready to use, scrape out the pith of the lemons with a knife and cut up the skin into small cubes. Immerse in olive oil a couple hours prior to using.
Recipe courtesy of Gerald Hirigoyen and Robert Petzold at Bocadillas