Mix the yeast with the water. Put the flour in a bowl. Mix the liquid clarified butter, yeast water and salt until the batter is smooth. Let the dough rise in a warm place for about 45 minutes.
Grease a tray with clarified butter. Roll out the dough and press it onto the baking sheet. Press the edge down well. Prick the dough base with a fork.
Cut the zucchini and tomatoes into slices, cover the dough in a flake shape, season with salt and sprinkle with cheese. Whisk the eggs with the creme fraîche and herbs and spread over the top. Bake on the bottom shelf in a hot oven at 220 ° C top / bottom heat for 40 minutes.