Wash the potatoes and boil in water for about 25 minutes. Then quench, peel and let cool. Wash the savoy cabbage, cut out the stalk in a wedge shape. Remove the individual leaves as much as possible, cut thick veins flat. Cut the rest of the savoy cabbage into small pieces. Cook everything in boiling salted water for about 10 minutes, drain. Cut potatoes into slices
Peel and finely dice the onion and garlic. Sauté in 1 tbsp. hot fat. Stir in tomato paste, dust with 1 tbsp. flour, sauté. Stir in tomatoes together with liquid and 200 ml water, bring to the boil. Chop the tomatoes coarsely. Season with salt, pepper and oregano. Simmer open for about 10 minutes.
Melt 60 g fat. Sweat 3 tbsp. flour in it. Stir in 1/2 l water, cream and stock, bring to the boil. Dice cheese corner and melt in it while stirring. Season to taste
Roughly grate the gouda. Pour some light sauce into a greased square casserole dish (approx. 30 cm long). Alternately layer savoy cabbage and potatoes with the two sauces. Finish with potatoes, light sauce and cheese. Bake the casserole in a preheated oven (electric cooker: 200 °C/recirculating air: 175 °C/gas: level 3) for approx. 30 minutes until golden brown