Making Ikea's Swedish Meatballs

INGREDIENTS:

FOR THE MEATBALLS:
• ½ cup breadcrumbs
• ¼ cup heavy cream
• 2 tablespoons grams Dijon mustard
• ½ teaspoon allspice
• 1 large egg beaten
• salt and ground black pepper
• 1 pound ground beef
• 1 pound ground pork
• 2 tbsp canola oil

FOR THE GRAVY:
• 2 cups beef stock
• ½ cup heavy cream
• 4 tbsp flour
• 2 tablespoons lingonberry jam

FOR THE MASHED POTATOES:
• 2 lbs yukon gold potatoes
• ½ stick butter
• ½ cup heavy cream