Break apart the minced pork and beef into a large bowl and stir in eggs.
Put the milk and the bread into a food processor. Let the bread soak for a minute while you add the garlic, Parmesan, ricotta, chile flakes, fennel seeds, salt, pepper, and lemon zest. Pulse everything until the mixture is just combined.
Add bread mix to the minced meat mixture, then combine. Roll into about 40 to 45 golf ball-size meatballs and chill in the fridge until you are ready to use them.
Preheat oven to 350º F (180º C). Heat half of the butter in a frying pan. Add 15 to 20 meatballs at a time over medium heat for 10 minutes, turning frequently, until golden brown. Remove them from the pan and transfer them to an ovenproof dish and bake for another 5 minutes while you repeat with the rest of the meatballs and butter until all of the meatballs are cooked. Set all meatballs aside and lower heat in the pan to medium-low.
Add flour to the frying pan and use a wooden spoon to beat it into the butter that's in the pan, scraping the brown bits off the bottom as you go. Once it is a dense, blobby paste, add stock along with the herbs and spices (chopped dill, nutmeg, and allspice) and whisk to combine. Increase heat to medium-high and stir sauce for 5 minutes or so, until it thickens.
Add sour cream, Parmesan, fennel fronds or dill sprigs, and 1/2 cup lingonberry jam. Whisk together and cook for 3 to 4 minutes, until thick and smooth. Season to taste with salt and pepper.
If your pan is ovenproof, you can now just place meatballs into the sauce and place the entire pan into the oven. If your pan isn't ovenproof, transfer everything to an ovenproof dish. Allow the meatballs to reheat for 5 to 10 minutes.
Serve meatballs garnished with fennel fronds or dill sprigs and either a good dollop of mashed potatoes or wide egg noodles. Spoon over gravy and enjoy with remaining 1 cup lingonberry jam on the side.
I absolutely love food and food styling and have been writing a blog with my own recipes since July 2012. I also have a Pinterest page at http://pinterest.com/fromthekitchen/ and a Facebook page here: