Try quince for a new twist to a forgotten fruit and it's delicious flavors. Add the paste to your cheeseboard, stewed meats, or as a simple dessert.
Place the quince, vanilla bean pod and seeds, and lemon zest in a 4 quart saucepan and cover with water. Bring to a boil over medium high heat. Reduce to a simmer, cover and cook until the quince are tender when poked with a knife, about 40 minutes.
Drain the quince in a colander and discard the vanilla bean. Puree the fruit and lemon zest in a food processor. Measure the puree by volume, return to the saucepan, and add an equal amount of sugar. (If you have 2 cups puree, add 2 cups sugar.)
Cook over medium-low heat, stirring with a wooden spoon until the sugar has dissolved, 1 to 2 minutes. Add the lemon juice and return the heat to low. Continue to cook, stirring occasionally, until the puree becomes a very thick paste, about 1-2 hours.
Meanwhile, position the rack in the center of your oven and heat to 125 degrees F. If your oven doesn't go this low, use the lowest temperature, and expect a shorter cooking time. Line a 8x8 glass or ceramic pan with parchment paper, grease with the butter.
Pour the quince paste (do not scrape the pot) into the dish, and smooth top with the wooden spoon. Bake until slightly dried and firm enough to slice, about 1 hour.
Remove from the oven and let cool to room temperature. Invert onto a cutting board and cut quince into four 2-inch wide strips. Wrap each strip in plastic wrap and refrigerate. The quince paste will last up to one month.