For the quiche with mushrooms, knead the ingredients for the dough, form into a ball and let rest in the refrigerator for 1 hour.
Cut the onion and garlic into small pieces and the mushrooms into pieces. Sauté the onions in the olive oil. Add mushrooms, garlic, cumin and rosemary.
Reduce heat and steam closed for 10 minutes. Season with salt and pepper. Preheat oven to 200 °C top and bottom heat.
Whisk cream with eggs, tomato paste, cornflour and salt. Add the cheese. Line a shallow baking dish (about 24 cm in diameter) with the dough, raising the edge about 2 cm.
Spread the mushroom mixture on the dough and pour cream mixture over it. Bake the quiche with mushrooms for about 30-35 minutes until golden brown.