I'd never cooked with either quinces or persimmons before but from their flavor profiles and conversations with purveyors at the farmers market, I thought they might be good together. Curiosity led me to this spread, and I was quite pleased.
We loved it atop toasted bread and creamy goat cheese but also thought it'd be lovely as a glaze on or "stuffing" for roast pork or chicken. —em-i-lis
In a large saucepan (~4 qt) over medium-high heat, toss the cubed and peeled quince with the sugar and water. Once the sugar is melted and things are starting to heat up, add the persimmon, gingers and pepper. Stir regularly while the fruits fall apart and the sauce thickens. Mash with a potato masher to help the quince along if need be (hard as rocks, that quince!).
When the consistency is to your liking -mine was spreadable but firm'ish- ladle into a glass container and let cool. Cover and refrigerate.