Onion: cut the tip off the onion, then peel the skin and discard. Use a hand held grater to grate it. Then measure ½ cup of the grated onion. Discard the rest.
Bread: add the sliced bread pieces to a medium bowl. Pour the grated onion over the top, then add the milk. Stir to combine then let sit for 1 to 2 minutes.
Meatballs: add the beef mince, pork mince, nutmeg, all spice, salt, pepper and egg to the wet bread onion mixture. Use clean hands to combine. Then portion a small amount and roll into a meatball. Place the meatball onto a clean chopping board and then repeat until all of the mixture is rolled into balls. Then place them into the fridge for 15 minutes. Note 7
Cook meatballs: place a large fry pan on the stove, turn the heat to high and add the avocado oil. Use tongs to transfer the meatballs into the pan. Work in batches if required. Cook for 5 to 8 minutes till the meatballs are golden brown and crispy on the outsides. Once cooked remove and place in a bowl lined with paper towel.
Gravy: without rinsing or cleaning the pan add the butter and let it melt. Turn the heat to medium, then add the flour. Next pour in the beef stock and Worcestershire sauce. Stir to consistently combine. Then pour in the cream.
Combine: once the sauce is consistently mixed together (it will thicken over time) add the cooked meatballs back to the pan. Then allow them to heat through.
Serve: spoon mashed potato into bowls, pop some steamed broccolini on the side and then dollop spoonful's of the Kottbullar and gravy on top. Season with black pepper and finely chopped parsley.