1. Preheat your oven to 350 degrees F.
2. Combine the onion, garlic, eggs, beef stock, and water in a food processor and mix until the onion and garlic is pureed, about 15 seconds. 
3. Add the breadcrumbs, sea salt, black pepper and allspice to the food processor and pulse about 5 times to combine well. 
4. Then add the ground meats and mix for 30 seconds, stopping to scrape down container with a silicone spatula halfway through, until all of the ingredients are combined and the meat has a smooth, paste-like consistency.
5. Use a cookie scooper or tablespoon measure to divide meat mixture into equal mounds for forming balls. 
6. Get a small bowl of water to wet your fingers. This will prevent the meat from sticking to your hands.  
7. Roll each meatball in your hands to smooth the outer surface.
8. Place lightly greased aluminum foil on a baking sheet or use a silicone baking mat and bake for 20 to 25 minutes or until the meatballs are just lightly browned.  
9. Allow meatballs to cool and wipe off any accumulated proteins (the whitish substance that’s often mistaken for fat) with a paper towel.  Now would be a good time to start boiling the water for the noodles. If freezing the meatballs for later, store in a freezer storage bag and when ready to use, thaw, then move to next step.  
10. Brown the meatballs in a skillet over medium heat for a couple minutes until brown all over, then move them to a bowl to rest. You can now use the skillet to make the gravy sauce.
11. Start boiling the water for noodles as per directions below.

For the gravy sauce and noodles

1. Bring 3 quarts of water to boil in a large pot or dutch oven. Add salt to taste, 1-2 tsps.
2. Add 1 tablespoon of butter and 1 tablespoon of olive oil to the skillet used to brown the meatballs and bring heat back up to medium. When the butter is melted, add the sliced mushrooms and stir to coat. Sprinkle with some salt and sauté the mushrooms until golden brown and most of the moisture is released. About 8-10 minutes. Remove from heat and set mushrooms aside in a small bowl.
3. Add noodles to boiling water directly after you’ve sauteed the mushrooms for the gravy. Let it come back to a boil. Cook egg noodles per package instruction times. You should have plenty of time to finish the gravy while the noodles are cooking. Drain noodles in a colander and set aside.  
4. Make the roux for the gravy by adding the other 3 tbsp of butter to the skillet and melt over medium heat.
5. When the butter is melted, add the flour and whisk continuously for 2-3 minutes until the roux is golden brown.
6. Slowly pour in the beef stock and keep whisking until smooth.
7. Whisk in the soy sauce, dijon mustard and cream and bring to a simmer to thicken.
8. Add the cooked mushrooms to the gravy and stir.  Then add the meatballs to the sauce and stir to coat. Allow them to simmer until warmed through.
9. Arrange noodles on a plate and spoon the meatballs and gravy over the noodles.  Optionally, garnish with parsley and serve with lingonberries or fruit preserves.