Step 1
Start by heating your oven to 350°F and lining a baking sheet with foil for easy cleanup. In a big bowl, combine the bread crumbs, egg, a quarter cup of chopped onion, water chestnuts, a quarter cup of applesauce, Parmesan, parsley, salt, mustard powder, and poultry seasoning. Add the ground turkey and gently mix everything together until just combined—don’t overwork it. Shape the mixture into meatballs about 1½ inches wide and set them on your prepared baking sheet. Pop them in the oven and bake for around 20 minutes, or until they’re cooked through (a meat thermometer should read 165°F in the center). While the meatballs cook, whisk together apple jelly, a cup of applesauce, cider vinegar, half a cup of minced onion, ketchup, chili sauce, tomato paste, brown sugar, Dijon, dry mustard, and a pinch of salt in a saucepan. Let the sauce simmer gently, stirring now and then, for about 10 minutes so the flavors can meld. When the meatballs are done, transfer them into the simmering sauce, cover, and let everything cook together for another 10 minutes. Finish by sprinkling the remaining parsley on top before serving.
