Fresh and Dried Mushroom Soup

Ingredients

• 1/2 cup dried porcini (or other imported dried mushrooms)
• 2 tsp vegetable oil
• 1 large onion (finely chopped)
• 4 garlic cloves (minced)
• 224 g fresh shiitake mushrooms (trimmed, halved and thinly sliced)
• 454 g fresh button mushrooms (thinly sliced)
• 1/4 cup dry sherry or chicken stock
• 1 1/2 cups chicken or vegetable stock
• 1 large tomato (cored, seeded and finely chopped)
• 1/2 tsp dried tarragon
• 1/2 tsp black pepper