Halibut with Vegetables and Porcini Brodo

Ingredients

• 1⁄4 cup olive oil
• 1 large carrot, diced
• 2 ribs celery, diced
• 1 fennel bulb, diced
• 1 onion, diced
• Reserved maitake stems
• Reserved green garlic tops, chopped
• 2 ounces dried porcini, soaked in hot water just to cover
• 1 small bunch fresh thyme sprigs
• 4 to 6 bay leaves
• Water as needed
• Salt and ground black pepper