• Tear bread into small pieces, place bread and milk in a medium sized mixing bowl and set aside, allowing bread to soak up liquid.  Using hands or a fork break bread up in milk so that it resembles a paste and there are not any large chunks of bread.
• Finely chop onion and measure 1 1/2 cups. In a large skillet add olive oil add onions. Cook on medium heat until onions are soft and starting to caramelize this will take about 10 minutes. Don't clean pan you can use it for browning meatballs.
• In a large bowl combine ground beef, ground pork, spices, cooled caramelized onions, egg, and bread milk mixture.  Combine with hands until all ingredients are thoroughly incorporated.
• Form meat mixture into 1 inch balls, place on baking sheets, put in freezer for 30 minutes.  

preheat oven to 400 ℉

• Remove meatballs from freezer. Add a tablespoon of butter to skillet over medium low heat. Add meatballs to pan in shifts, brown and remove back to sheet pan until all the meatballs have been browned. Meatballs do not need to be cooked through just browned on the outside. 
• When the meatball browning process is complete place sheet pan of meatballs into preheated 400 degrees F oven for 20 minutes.
• While meatballs are baking you can start to prepare the gravy by melting remaining 7 tablespoons of butter in skillet you browned meatballs in.
• When butter has melted add 2/3 cup flour, whisk continually creating your roux. When the roux is golden in color, this will take about 10 minutes. Whisk in 4 cups of beef stock. Whisk until smooth and gravy starts to thicken, turn to low.
• Remove meatballs from oven and pour off any pan juices to the gravy. Whisk to combine. Turn burner to low heat and add in sour cream, whisk sour cream into gravy. Taste and add salt and pepper to our taste.
• Return meatballs to skillet with gravy. Cover and allow to simmer for 10-15 minutes.