Mix flour, milk and mineral water. Stir in eggs, season with salt and pepper. Heat 1 teaspoon of oil in a coated pan (approx. 20 cm Ø). Add 1/4 of the dough and bake a pancake.
Process the rest of the dough and 3 teaspoons of oil in the same way. Keep warm. Clean, clean and slice the mushrooms. Peel and chop the onion. Peel and chop garlic. Heat 1 tablespoon of oil in a frying pan.
Fry the mushrooms, onion and garlic in it. Add pizza and fajita sauce. Add the jalapeños. Reduce the sauce for about 5 minutes. Dab mozzarella dry and cut into slices. Fold the pancakes into bags and add some vegetable mixture to each bag.
Place the pancakes in a greased casserole dish and pour the rest of the vegetable sauce over them. Spread mozzarella on top. Bake in a preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) until the mozzarella has run off.
Garnish with herbs.