Remove the chard from the stalk and roughly chop it. Cut the spring onions into slices, finely chop the onions and garlic, grate the cheese.
Heat 2 tablespoons of olive oil in a pan. Add onion and garlic and sauté. Then add the chanterelles and fry them until they whistle. Next, add the chard and leek, fry for 5 minutes and season with a pinch of salt and marjoram. Set the vegetable mixture aside to cool.
Next, whisk the eggs with milk, creme fraîche, cheese, nutmeg, 1 - 2 teaspoons of salt and pepper. Also put aside.
For the dough, put flour, egg yolk, water, 6 tablespoons of olive oil and a pinch of salt in a bowl and knead to form a smooth dough. Let the dough rest for about 30 minutes.
Preheat the oven to 180 ° C. Roll out the dough thinly and place in a greased springform pan (the edge should be about 5 cm high). Pre-bake the dough for about 10-15 minutes.
Spread the vegetable mixture on the pre-baked dough, pour the egg-cream-cheese mixture over it and bake the tart for 40 minutes. After the baking time, remove the springform pan, cut the cake and serve immediately.