Supreme seafood chowder

Name: Supreme seafood chowder
Ingredients: 45 mL (3 tbsp.) unsalted butter; 2 celery stalks, finely diced; 1 onion, finely diced; 45 mL (3 tbsp.) all purpose flour; 750 mL (3 cups) milk; 250 mL (1 cup) fish broth prepared with cubes; 2 yellow-fleshed potatoes, peeled and diced; 7 mL (1 1/2 tsp.) salt; 675 g (1 1/2 lb) fresh fish and seafood mix (cubed white fish and salmon fillets, scallops, shrimp, and clams); 20 mL (4 tsp.) finely chopped chives; 20 mL (4 tsp.) finely chopped fresh parsley