Peel, wash and halve the potatoes. Cook in salted water for about 20 minutes.
In the meantime, cut the sausages into pieces. Peel and dice the onions. Drain the corn, wash and clean the spring onions and cut into rings.
Heat the oil in a roasting pan. Fry the sausages all over. Dust with flour. Stir in the beer, 1/4 l water and stock. Simmer for about 10 minutes, stirring occasionally.
Fold in the corn and spring onions, heat. Season to taste with salt, pepper, ketchup and sugar.
Drain the potatoes and mash to a puree with milk and butter. Season with salt and nutmeg. Arrange everything together.