Soak the dried porcini in boiling water for twenty minutes.
Sauté the onion, celery, carrot and garlic in the olive oil.
Add the portobellini mushrooms and sauté until softened.
Drain the porcini (reserving the liquid) and chop finely.
Add the porcini and soaking liquid,tomatoes, tomato paste and red wine.
Add the oregano and a pinch of nutmeg, bring to the boil and simmer,uncovered, for thirty minutes.
Season to taste and serve on spagetti with lots of freshly grated parmesan cheese