Bring the stock to the boil in a small saucepan, remove from the heat. Add the porcini, stir and set aside for 10minutes to rehydrate. Drain and reserve the soaking liquid.
Finely chop the porcini and add to a mixing bowl with the beef mince, egg, garlic, almond meal, soda water, salt and pepper. Roll into 36 balls.
Heat the butter and olive oil in a frying pan or wide shallow saucepan over medium high heat. Cook the mushrooms, garlic and thyme for 5 minutes until beginning to colour. Add the paprika and onion powder, cook for a further minute.
Deglaze the pan with white wine, bubble away for a couple of minutes before adding the passata and reserved porcini liquid (leave the last little bit behind because it can be gritty).
Add the meatballs, bring to a simmer. Reduce heat to medium, cover and cook for around 10 to 15 minutes until the meatballs are cooked through.
Remove from the heat and cool slightly before stirring through the sour cream. Season with salt and pepper to taste, serve with parsley.
This recipe has the net carbs calculated by Ali Irvine.
NOTE: THIS IS BASED ON THE INGREDIENTS WE USED, NUTRITIONAL INFORMATION MAY VARY DEPENDING ON THE INGREDIENTS USED.