Smoked haddock chowder recipe

Name: Smoked haddock chowder recipe
Prep time: 10 min
Cook time: 17 min
Total time: 27 min
Cuisine: American
Ingredients: 1tbsp olive oil; 1 onion, peeled and chopped; 2 sticks celery, chopped; 1 litre (1¾ pints) milk; 4 medium potatoes, peeled and cubed; 2tbsp instant thickening granules (eg, McDougalls); 2 x 125g (4oz) smoked haddock fillets, skinned; 2 x 125g (4oz) salmon fillets, skinned; 300g (10oz) frozen sweetcorn; Salt and freshly ground black pepper; 2tbsp chopped fresh parsley (optional)