i made a poor mans version today . i steamed the fish ,melted some butter in a pan,made a paste with some flour,added the stock from the fish with a drop of milk, whisk to thicken,add some dried parsley mix with fish,top ped it with mashed potatoe and greated cheese and popped it in the oven,not as elaborate as hells kitchen but enjoyed it
veloute is like a white sauce, you know when you make a roux - when you melt butter, add flour and whisk in milk thats a bechamel - add cheese and you have a mornay, instead of milk you use stock - in this case you'd use fish stock.
Yeah like Natalie I'm sure he was using equal parts of those three ingredients - I remember him saying to boil the wine down to a syrup, add fish stock and again boil down to a syrup, and then add the cream for a few minutes.
Sorry I havn't replied sooner and you've probably made it by now ! It is called Veloute and its equal quantities of wine and fish stock then add cream at the end. Reduce the wine and fish stock separately then put together adding the cream at the end.