Swallows of seahouses fish chowder

Name: Swallows of seahouses fish chowder
Ingredients: 500g smoked haddock, diced; 500ml whole milk; 100g butter + 15g; 6 cloves garlic, finely chopped; 2 white onions, finely diced; 4 sticks celery, sliced; 500g Carroll’s Heritage Potatoes, peeled and 1”cubed (weight after peeling); 500ml single cream; salt and pepper to taste; 1g saffron; 2 leeks, diced; 500g fresh clams; 500g cod fillet, diced; 250g raw tiger prawns; 200g smoked mussels; 1 bunch fresh parsley, finely chopped; 1 sourdough loaf (Geordie Bakers)