The confiture aisle of a good French food hall is a spectacle to rival Mont-Saint-Michel. Expect a wall of glass jars in every jewel tone from scarlet fraise de bois to lucent jellies of soft-set violet petals. Black cherry, white peach, purple fig and four varieties of plum in four rainbow shades. Then come lines of exotically spiced jams: rhubarb and cardamom, apricot with lavender or thyme, rum-spiked raisin and banana, and darkly reduced apples cooked with Calvados and