The sweet-bitter and floral flavors of this caramelized lemon paste take the best qualities of lemon and amplify it times 10. Make this paste and stir it into plain pasta, spoon it over roasted broccoli or other vegetables, or stir into yogurt sauces or salad dressings to add a punch of flavor.
Caramelized Lemon Paste
Wash the lemons under hot running water then dry thoroughly. Set a Microplane grater over the bowl of a food processor or blender, and finely grate the zest from all the lemons so it falls into the processor. Alternatively, remove the zest in large strips with a vegetable peeler, but be careful not to take any of the white pith underneath. If you do, trim it off with a paring knife and discard.
Halve the lemons, then juice them, straining out any pulp or seeds; reserve the juice (you should have about 1 cup plus 2 tablespoons juice). Trim off and discard the ends from the spent pith shells, then cut the shells into ¼-inch pieces.
Heat the oil in a large saucepan over medium-high heat. Add the chopped lemon and sprinkle with the salt. Cook, stirring occasionally at first and then constantly toward the end, until all the pieces are evenly, deeply caramelized, 8 to 10 minutes.
Scrape the contents of the pan into the food processor with the zest. With the processor running, slowly drizzle in the reserved lemon juice and continue processing until the paste is as smooth as possible, about 20 seconds.
Transfer the paste to an airtight container, pressing on it to compact it, then drizzle enough olive oil over the surface to cover (this helps preserve the paste). Store in the refrigerator for up to 2 weeks.