Chorizo, new potato & haddock one-pot

INGREDIENTS

• 1 tbsp extra-virgin olive oil , plus extra to serve
• 50g chorizo , peeled and thinly sliced
• 450g salad or new potatoes , sliced (I used Charlotte)
• 4 tbsp dry sherry , or more if you need it (or use white wine)
• 2 skinless thick fillets white fish (I used sustainably caught haddock)
• good handful cherry tomatoes , halved
• 20g bunch parsley , chopped
• crusty bread , to serve