Fry the fresh mushrooms quickly without fat. Season a little salt and pepper and deglaze with the lemon juice. Soak the porcini mushrooms in water and then cut them into small pieces. Keep soaking water. Also cut the tomatoes into small pieces.
Finely dice the onion and garlic and sauté in 2 tablespoon butter. Add the risotto rice and let it turn to glass. Deglaze with the white wine and let it boil down. Add 6 tablespoons of the boletus water. Then gradually add small portions of the vegetable stock and bring to the boil completely while stirring constantly, then top up with the stock again.
With the last portion of stock, add the fresh, fried mushrooms, sun-dried tomatoes and the porcini mushrooms. Let it boil down again. Stir in the remaining butter and the grated Parmesan.