Dice the onion and dice the garlic. Core and dice the peppers. Chop the cauliflower into florets and dice the mushrooms, roughly chop both in a blender and prepare.
Preheat the oven to 220 ° C top / bottom heat. Prepare a 25 cm springform pan.
Steam the onion in a large pan until translucent. Then sauté the garlic very briefly. Add the cauliflower and mushroom mixture and reduce the resulting liquid on a low flame while stirring constantly. Add paprika, season with salt, pepper, vinegar, marjoram and a pinch of cumin, stir well. Stir in the stock and crème fraîche and let everything simmer for about 5 minutes.
Mix in the mini mozzarella balls and simmer for another 10 minutes, stirring constantly.
Grease the springform pan with a little olive oil. Line the bottom of the springform pan with a round sheet of puff pastry, cut out strips for the edge from the other.
Put the contents of the pan in the springform pan and place a grid on top with the remaining puff pastry.
Whisk the egg yolk with a small dash of cream and brush the surface with it. Place in the oven on the 2nd lower rack and bake for about 25 minutes.