Mix eggs, milk and 1 pinch of salt in a bowl. Add flour to the egg-milk mixture, mix to a smooth dough and let rest covered for about 30 minutes
In the meantime, peel and finely dice the onion. Peel garlic and chop finely. Wash thyme, shake dry and chop finely. Heat 1 tablespoon of oil in a saucepan. Fry the onion, thyme and garlic until transparent, stirring continuously. Deglaze with tomatoes and stock. Season with sugar, salt and pepper. Simmer for about 15 minutes, stirring occasionally. Peel the carrots. Clean and wash the zucchini. Slice the vegetables into thin slices. Blanch the carrots in boiling salted water for about 1 minute. After about 30 seconds add the zucchini. Drain and rinse with cold water
Heat 1 tablespoon of oil in a pan (20 cm Ø). Add 1/4 of the dough and bake on both sides until golden brown. Bake 4 pancakes one after the other. Let them cool down a bit and place them next to each other on the work surface. Cover evenly with ham. Cover 2 pancakes with carrot slices and 2 with zucchini slices. Roll them up and cut them into thirds. Season sauce with salt and pepper. Pour 2/3 into an ovenproof dish (approx. 18 x 25 cm). Place the rolls in the dish with the cut edge facing upwards. Spread the rest of the sauce on top. Grate the Gouda and sprinkle over the rolls. Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: see manufacturer) for 20-25 minutes