Mix eggs, 1/8 litre milk, mineral water, salt, flour and baking powder until smooth. Heat oil in portions and bake 5 pancakes from the dough one after the other. Peel, wash, halve and slice the carrots.
Clean, wash and cut the peppers into small pieces. Clean, wash and chop the zucchini. Cook carrots and peppers in a little salted water for 5-6 minutes. Add peas and zucchini to the carrots for the last 3 minutes.
Wash the chervil, put something aside for garnishing. Chop the rest roughly. Add to vegetables. Melt the fat in a pot. Sweat flour in it. Deglaze with stock and 1/8 litre milk while stirring. Bring to the boil and simmer for 4 minutes.
Stir in cream cheese. Season to taste with salt and pepper. Drain the vegetable water. Mix 1/3 of the sauce with the vegetables. Spread the vegetables on the pancakes and roll them up. Cut the pancakes into 3 pieces and put them in a greased casserole dish.
Spread the rest of the sauce over it. Cut the mozzarella into pieces and spread on the rolls. Bake in the preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for approx. 10 minutes.
Garnish with chervil.