Set the cooker to Warm for the party and put out a cup of cocktail toothpicks beside it. Guests serve themselves.
For dinner instead of a party bite, spoon the meatballs and sauce over steamed white rice or mashed potatoes with green beans alongside.
Use a 4-quart slow cooker, not a 6- or 7-quart. In a big crock the sauce spreads thin and scorches at the edges.
Do not cook this on High the whole time. Canned cranberry sauce is high in sugar and will burn.
Leave the jalapeno seeds and ribs in for real heat, or scrape them out for a warm background note, which is how most people prefer it.
Whole-berry cranberry sauce works in place of jellied and gives a chunkier glaze.
Bottled chili sauce means the sweet tomato-based American condiment in the ketchup aisle, not Asian sweet chili sauce or sriracha.
Leftovers keep 4 days refrigerated and reheat gently in a saucepan with a splash of water. They also freeze well for 3 months.