1Season the mushrooms with salt and pepper, and sauté in a hot saucepan with butter over medium heat until golden brown. Add the hard cider, and simmer until reduced by 1/2. Add the heavy cream, and cook until the sauce is very thick and coats the mushrooms. Reserve.
2Season the fish with salt and pepper, and saute in a saucepan with olive oil until done.
3Trim the bread slices to match the size of the fish portions. Toast in a pan with the butter over medium heat.
4Place the fish portions on top of the toasts, then cover with mushrooms. Sprinkle the cheese, and melt using a blow torch or under the broiler. Sprinkle with chives, and serve immediately.