Mix butter with salt, flour and 4 tablespoons of water and knead quickly into a smooth dough. Press dough into a 28 cm (approximately 11 inches) diameter quiche dish, forming an edge up the side. Refrigerate 1 hour.
Clean mushrooms, cut in half and sprinkle with lemon juice. Cut sage leaves into thin strips. Peel garlic and chop finely. Rinse tomatoes and chop finely.
Cut a circle the size of the quiche dish from parchment paper. Place on the dough, sprinkle with dried beans and bake in preheated oven at 180°C (approximately 350°F) for 10 minutes. Remove beans and parchment paper.
Separate the eggs. Whisk egg yolks with cream cheese and season with salt and pepper. Beat egg whites until very stiff and fold into yolk mixture. Distribute mushrooms and tomatoes on the crust, pour in egg mixture, sprinkle with sage and bake at 180°C (approximately 350°F) for about 40 minutes.