Soak the breadcrumbs: In a bowl, stir breadcrumbs and milk. Let sit 3–5 minutes until the crumbs are plump and soft.

Mix the meatballs: Add ground beef, ground pork, egg, minced onion, garlic, salt, pepper, allspice, and nutmeg to the breadcrumb mixture. Gently mix with your hands until just combined. Don’t overwork.

Shape: Form 1- to 1.5-inch meatballs. Aim for uniform size so they cook evenly. You should get roughly 30–36 meatballs.

(Optional) Brown for extra flavor: Heat butter or oil in a large skillet over medium-high. Brown meatballs in batches, turning to get color on multiple sides. No need to cook through. Transfer to the slow cooker as you go. If skipping browning, place raw meatballs directly into the slow cooker.

Whisk the sauce base: In a bowl, whisk together beef broth, Worcestershire sauce, Dijon, onion powder, and garlic powder. Pour over the meatballs.

Slow cook: Cover and cook on Low for 4–5 hours or on High for 2–3 hours, until the meatballs are fully cooked and tender.

Thicken the gravy: Stir cornstarch with cold water to make a slurry. Set the slow cooker to High (if not already). Gently stir in the slurry and the cream. Cook 15–25 minutes, stirring once or twice, until the gravy is silky and coats the back of a spoon.

Season to taste: Add salt and black pepper as needed. If you want more tang, add another small splash of Worcestershire or a tiny dash of Dijon.

Serve: Spoon meatballs and gravy over egg noodles, mashed potatoes, or rice. Sprinkle with parsley and serve with a spoonful of lingonberry jam on the side.