Heat half of the olive oil in a large skillet over medium high heat. Add in onions, and cook for about 4-5 minutes. Wipe skillet and set aside.

In a large bowl, mix together the pork, beef, cooked onion, Panko, egg, nutmeg, allspice and salt and pepper. Roll the mixture into 24 1” meatballs.

Heat remaining olive oil in skillet. Add meatballs into pan, in batches, and cook until all sides are browned. About 5 minutes. Transfer to a plate and set aside.

Now melt butter in skillet, and then whisk the flour into the melted butter. Cook until lightly browned, about 1 minute. Slowly pour in the beef broth while continuing to whisk, until gravy is mildly thickened, about 3 minutes. You may need a bit more or less broth to achieve the desired texture of gravy.

Whisk in the sour cream, and season with salt and pepper as desired.

Add in the meatballs, and stir around gently. Cook, remembering to stir occasionally, for about 10-12 minutes, or until meatballs are cooked through.