Fennel and Potato Stew with Olives and Preserved Lemon

Ingredients

• 2 bulbs fennel
• 3 waxy yellow potatoes (such as Yukon Gold)
• 1 tablespoon olive oil
• 2-3 tablespoons butter
• salt
• freshly ground pepper
• 2 bay leaves
• 1 tablespoon chopped fresh sage, plus extra leaves for garnish
• 2 garlic cloves, peeled and finely chopped
• 1 dried red chili
• 4 plum tomatoes (or 14-oz canned plum tomatoes)
• 1/2 preserved lemon, chopped
• 1/2 cup vegetable broth
• 12 black olives (kalamata, Nicoise, or Ligurian)
• freshly grated parmesan to serve
• 2 tablespoons basil oil (recipe following)
• 3 bunches fresh basil
• 1 garlic clove
• freshly ground black pepper
• 3/4 cup good quality olive oil