For the shortcrust pastry base, dice 125 g cold butter. Knead egg, butter, 250 g flour and 4-6 tbsp. cold water to a smooth dough. Roll out round (approx. 32 cm Ø) on a floured work surface and place in a greased casserole dish (approx. 26 cm Ø).
Place the mould in a cool place for about 30 minutes.
For the goulash, peel 4 onions and cut into short strips. Cut the sausage into thick slices. Heat 4 tablespoons of butter in a frying pan and fry the sausage for about 10 minutes while turning. After about 5 minutes add onions.
Dust with 2 tablespoons of flour. Stir in tomato paste, roast for about 2 minutes and deglaze with beer and tomatoes. Bring to the boil and simmer for about 2 minutes. Season to taste with salt, pepper, caraway and sugar.
In the meantime, line the dough in the ovenproof dish with baking paper and pour in dried peas. Bake blind in the preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: see manufacturer) for approx. 20 minutes.
Clean and wash spring onions and cut them into small rolls. Coarsely grate the cheese. Mix spaetzle, spring onions, except for something to sprinkle, and cheese. Season with salt and nutmeg. Remove dry peas and baking paper.
Pour goulash into the mould and spread the spaetzle mixture on top. Bake in the oven at the same temperature for another 30 minutes.
Peel the remaining onion and cut into strips. Heat 1 tablespoon butter and melt the onion strips in it for about 5 minutes while stirring. Spread the melted onions on the casserole and sprinkle with the remaining spring onion rings.