Heat the olive oil in a casserole and soften the onions for about 15 minutes. Add the garlic, cook a further 5 minutes, then add the fresh mushrooms and let them sweat gently with the onions, stirring often so that they cook evenly. Drain the dried ceps, keeping their soaking liquid. Squeeze the water out of the soaked ceps and chop coarsely, then add to the other mushrooms.
Add the tom