Mix egg, 125 ml low-fat milk, 1 pinch of salt, 75 g flour and baking powder well. Leave to swell for about 15 minutes. Put spinach and 4 tablespoons of water in a pot. Cover and cook over low heat for about 15 minutes.
Wash, clean and slice the tomatoes. Cut sheep's cheese into cubes. Stir mineral water into the pancake batter. Heat the oil in portions in a pan. 1/4 of the Pfa
Bake 3 more pancakes. Melt butter in a pot, dust with 25 g flour and sauté while stirring. Gradually add 125 ml milk and 250 ml water while stirring. Bring to the boil, stir in broth and simmer for 5 minutes.
Season spinach with salt and pepper. Spread about half of the spinach on the pancake. Spread tomatoes, except for 3-4 slices, and sheep's cheese, except for 1 tablespoon. Roll up the pancakes.
Spread the remaining leaf spinach in a mould. Place the rolls, remaining tomatoes and feta cheese on top, pour sauce over it. Bake in the preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for about 15 minutes.
Serve garnished with marjoram.