This jam is adapted from Michael Harlan Turkell's Acid Trip, his scholarly (but not too serious), deep dive book on vinegar. He serves it with a dollop of creamy fresh ricotta on crisp crostini, one of the best appetizers we can think of. We once served those at a fundraiser, and 400 pieces were devoured by enthusiastic guests in about 20 minutes flat! Spoon this alongside grilled pork or chicken like a chutney, or use it to fill a sweet/savory breakfast pastry. Don't even think about omitting the vinegar; it adds needed complexity to keep the jam from becoming cloying.