copycat of ikea's swedish meatballs

This recipe is delicious.  The meatballs are so tender and moist and the sauce is a perfect compliment.  The story (from Food Network Magazine) goes like this:  These meatballs have always been a favorite at Ikea stores ever since an in-store chef developed the recipe in Switzerland in 1985.  Although the store's cookbook which was published in 2000 included a meatball recipe, it was not the recipe served at their restaurants.  The recipe is top secret so Food Network Kitchens made a copycat recipe.
When I visited my parents this summer I noticed that they have dozens of Ikea's Swedish Meatball packets in their pantry.  I had no idea they loved their meatballs so much.

ikea's swedish meatballs (Food Network Magazine, October 2011)
1 cup breadcrumbs
2 tablespoons unsalted butter
1/3 cup minced white onion
2 cloves garlic, minced
1/4 teaspoon ground allspice
kosher salt and freshly ground white pepper
1/2 cup milk
1 teaspoon Worcestershire sauce
3/4 pound lean ground beef
1/2 pound lean ground pork
1 large egg plus 1 egg white, beaten
vegetable oil for brushing

gravy
2 tablespoons butter
2 tablespoons flour
1 1/2 cups low-sodium beef broth
1 teaspoon Worcestershire sauce
1/4 cup heavy cream
kosher salt and freshly ground pepper
2 tablespoons chopped fresh parsley (optional)
lingonberry jam, for serving (optional)

Make the meatballs:  Put the breadcrumbs in a large bowl.  Heat the butter in a skillet over medium heat.  Add the onion, garlic, allspice, 2 teaspoons salt and 1/4 teaspoon white pepper and cook, stirring until soft, about 5 minutes.  Add the milk and Worcestershire sauce and bring to a simmer.  Pour the milk mixture over the breadcrumbs and stir to make a thick paste; let cool.  Add the beef, pork egg and egg white to the bowl and mix until combined.
Brush a baking sheet with vegetable oil.  Roll the meat into 1-inch balls and arrange on the prepared baking sheet.  Cover with plastic wrap and refrigerate at least 1 hour (I omitted the refrigeration).
Preheat the oven to 400 degrees.  Bake the meatballs until cooked through, about 20 minutes.
Make the gravy: Melt the butter in a large skillet over medium heat.  Add the flour and cook, whisking until smooth.  Whisk in the beef broth and Worcestershire sauce and bring to a simmer.  Add the cream and meatballs.  Reduce the heat to medium low and simmer until the gravy thickens, about 10 minutes.  Season with salt and black pepper.  Transfer to a serving dish.  Sprinkle with the parsley and serve with lingonberry jam if desired.