Place the figs in a large pot. Pour the sugar over the figs, cover the pot, and let sit overnight.

Heat the pot on the stovetop over medium heat. Cook, stirring constantly, until the sugar dissolves (this only takes a few minutes). Reduce the heat to low, add the lemon slices, and cook for about 2 hours (or until the syrup is thick). If the figs are particularly large, I like to use a wooden spoon or a potato masher to gently break apart the big chunks as the figs soften. If you have a deep fry or candy thermometer, you’re looking for a jelling point of 220-225°F.

Divide the figs and syrup between 3 sterilized 8-ounce glass jars, leaving ¼-inch of headspace at the top of each jar. Wipe the rims clean with a damp cloth, then secure the lids and bands.

Process in a boiling water bath for 10 minutes (or 15 minutes if your altitude is above 6,000 feet). Carefully remove the jars to a towel on the counter. Let stand, undisturbed, for 12 hours at room temperature. Check the seals after 12 hours by pressing the center of the lids. If the lid gives or the center button remains popped up, store in the refrigerator for up to 1 month. Properly sealed jars will keep in a cool, dark place for up to 8 months. Refrigerate after opening.