In a large pot over a medium heat, add the olive oil and melt the butter and brown off the onion and carrot. Once brown add the flour stirring so the flour soaks up all the butter and turns into a roux. Add the wine. Add a little fish stock and stir to thick paste. Gradually add the rest stirring to ensure no lumps form. Add bay leaf.
Using a whisk, add milk and cream, a third at a time, to form a smooth glossy base.
Turn the heat down to low and add chopped mussels, prawns,scallops, squid, wholegrain mustard, pepper, nutmeg, garlic and chilli. Bring to a gentle boil, being careful not to boil too rapidly or it will split.
Cook for 5 minutes, then add fresh fish and cook for a further 3 minutes. If it becomes too thick, add some extra stock or water to thin.
Season to taste with sea salt and garnish with parsley and paprika.