1/2 quantity Sour Cream Pastry (Sour Cream Pastry link)
50g dried porcini mushrooms
1&1/2 tablespoons verjuice
200g shelled walnuts
1 slice white bread with crusts on (about 75g)
60 ml milk
4-5 slices prosciutto
2 tablespoons lemon zest
1 clove garlic
1/2kg button mushrooms butter
2 tablespoons lemon thyme
freshly ground black pepper
Make and chill the pastry as instructed, then line a 20 cm loose- bottomed flan tin. Chill the pastry case for 20 minutes. Preheat the oven to 200C. Blind bake the pastry case for 15 minutes, then remove the foil and beans and return the pastry case to the oven for a further 5 minutes. Remove from the oven and reset the temperature to 220C. Reconstitute the dried porcini mushrooms in the verjuice for 30 minutes.
Dry-roast the walnuts for 6-8 minutes, then rub off their skins with a clean tea towel.
Toast the bread in the oven until golden, then cut it into cubes and soak in the milk until softened, then squeeze out the milk.
Slice the prosciutto finely. Blend the soaked toast, prosciutto, porcini, lemon zest and walnuts in a food processor to make a paste, then set it aside. Chop the button mushrooms and sauté them with the garlic in a little butter over quite a high heat (do them in batches so that they don’t stew), then season well. Toss the reconstituted boletus mushrooms in a little more melted butter, then season and puree them in a food processor. To assemble the tart, spread the walnut and prosciutto paste over the base, then brush with the porcini puree and arrange the sautéed mushrooms on top. Sprinkle with lemon thyme, season with black pepper. Bake for about 20 minutes at 200C until the edge of the pastry case is golden brown.
Serve warm or at room temperature.