Sausage and Fish One-Pot - Purnell's

Ingredients

• 1 tbsp extra-virgin olive oil, plus more for garnish
• 1/2 pound Purnell’s Italian hot sausage
• 2 large cloves garlic, crushed
• 1 medium onion, thinly sliced
• 1 1/2 pounds baby red or Yukon gold potatoes, thinly sliced
• Salt
• freshly ground black pepper
• 1/2 cup dry vermouth or dry white wine
• 1 pint cherry tomatoes, halved
• 4 haddock or cod fillets
• A handful flat-leaf parsley, chopped
• 1/2 lemon
• Crusty bread, to pass at table