Put the Brussels sprouts in 1/8 litre of boiling salted water and cook for 8-10 minutes on a low heat. Cut the bacon into small cubes and fry them crisply in a pan without fat. Remove from the pan and keep warm.
Peel onion and cut into rings. Put them together with the sausages into the frying fat and fry them all around for about 5 minutes at medium heat. Put 150 ml water, milk and some salt in a pot and bring to the boil.
Remove the pot from the heat and stir in the puree powder with a whisk. Add fat and stir in. Season to taste with nutmeg. Drain the Brussels sprouts and mix with the bacon cubes. Arrange the sausages, Brussels sprouts and puree together with the onions on a plate and serve.