1. Peel and slice the potatoes, wash and dry. Brown them in a pan with chopped onions, extra virgin olive oil, and 40 g of butter. Cover halfway; let them become tender, without browning. Season with salt and pepper.2. Preheat the oven to 200°C.3. In a bowl, sift the flour with salt and pepper. Create a well. Pour in extra virgin olive oil, beaten eggs and egg yolks. Mix and add the milk slowly to form a smooth paste.4. Butter a tart pan with a removable bottom. Sprinkle the bottom and edges with breadcrumbs; shake off excess. Pour in half of the paste and bake for 10 minutes.5. Fill the tart with potatoes and goat cheese sliced into rounds; cover with the remaining paste. Bake and cook for 25 minutes.6. Remove from the oven, unmold, and serve hot.