Fish and Potato Stew

Ingredients

• 2 medium potatoes, peeled and coarsely chopped
• 4 tablespoons olive oil
• 1 medium onion, sliced
• 0.5 cup pitted black olives
• 3 cloves garlic, finely chopped
• 1 (14.5 ounce) can Italian plum tomatoes, chopped
• 0.5 cup white wine
• 0.5 cup fish stock
• 2 tablespoons tomato paste
• salt and freshly ground black pepper to taste
• 1.25 pounds whitefish fillets, skinned and deboned