Apple Mostarda

With a vegetable peeler, remove long (end to end) strips of lemon peel, being careful not to get any pith. Continue around the whole lemon. I had eight strips. Stack strips and thinly cut crosswise (toothpick width). You should have about 1/4 cup.
Peel and core apples. Finely chop into uniform pieces about 1/4". You should have a little more than 2 cups. Place in a glass bowl; add lemon pieces, sugar and vinegar. Stir to combine.
In a 1 cup pyrex measure heat 1/4 cup water in the microwave for 15-20 seconds. Add raisins and grappa. Stir to combine and set aside.
In a heavy bottomed saucepan, temper mustard seeds by heating oil over medium heat. Add mustard seeds and cook for about a minute. Seeds should sputter a bit. Scrape in apple mixture, raisin mixture and shallots. Bring to a boil then reduce to a simmer and cook for 25 minutes, until most of the liquid has evaporated. Add Dijon mustard and butter and cook for 10 minutes more. Let mostarda cool a bit before enjoying or transferring to a clean glass jar with a lid. Enjoy warm or at room temperature with cheese and bread, or grilled or roasted meats. Mostarda should keep for a week in the refrigerator.