Preheat oven to 200 degrees.

To prepare lemons, scrub skin with a stiff brush until no wax remains. Placing them in a bowl filled with a mixture of one part vinegar to 3 parts water and dipping your brush into the mixture as you scrub is helpful.

Cut lemons as directed. In a small baking dish or casserole, add the lemons and toss with salt and if using, sugar. Add lemon juice and bake, covered, stirring now and then until the skins are softened, about 3 hours.

Let cool and transfer, with juices, to an airtight container and refrigerate. As an additional safety measure, keep refrigerated. It’s said preserved lemons keep indefinitely, but are best used within six months.

Note: If you’d like to make a quicker preserved lemon, slice lemons across or chop and continue with the recipe as directed. The smaller pieces will require less cooking time.