Mum's Swedish Meatballs

Melt butter in a skillet over medium heat; cook and stir onion in the melted butter until tender, 5 to 10 minutes.

Place bread cubes in a bowl; pour 1/2 cup evaporated milk over bread cubes. Set aside until bread cubes absorb milk.

Mix ground beef, ground pork, cooked onion, bread cube mixture, eggs, Worcestershire sauce, parsley, nutmeg, allspice, salt, lemon pepper, and ground black pepper together in a large bowl. Form mixture into golf ball-sized meatballs.

Heat olive oil in the same skillet used for onion over medium-high heat; cook meatballs in the hot oil, turning with tongs, until all sides are browned, 10 to 15 minutes. Pour in beef stock and simmer until meatballs are cooked through, 15 to 20 minutes. Transfer meatballs to a serving bowl, reserving liquid in the skillet.

Remove 1 cup beef stock from skillet; whisk flour into the 1 cup stock until smooth. Pour flour mixture back into skillet, whisking until mixture is smooth. Gradually whisk remaining evaporated milk and sherry into beef stock mixture. Simmer, stirring occasionally, until gravy is warmed and smooth, 5 to 10 minutes. Pour gravy over meatballs to serve.