Fusilli with porcini mushrooms and red prawns

Ingredients

• 600gr of fresh short fusilli casarecci
• 16 red prawns
• 1 big sweet porcini mushroom
• 1 garlic clove
• 1/4 onion
• 2 tablespoons extra virgin olive oil
• 30 gr. of butter
• 6 small red tomatoes
• 1 small glass of French Cognac
• parsley
• a tablespoon of cream
• grated Parmesan cheese