Cod and Tomato Chowder

Name: Cod and Tomato Chowder
Ingredients: 3 tbsp olive oil; 2 celery sticks, trimmed and roughly chopped; 2 medium onions, peeled and roughly chopped; 2 large carrots, peeled and roughly chopped; 2 large waxy potatoes, peeled and roughly chopped; 1 yellow pepper, roughly chopped; 2 thyme sprigs; 1 bay leaf; 400 grams tinned choped tomatoes; 900 ml fish or chicken stock; 150 grams green beans, cut short; 2 courgettes, roughly chopped; 1 dash tobasco sauce (optional); 600 grams cod fillets, skinned and deboned; 1 bunch flat leaf parsley, roughly chopped