Counter intuitive Salmon with Duxelles jacket

Since Salmon has become ubiquitous and is acknowledged as good for us we all probably eat lots of it. It's a fish that's hard to screw up, probably environmentally friendly enough in the farm raised version, but when you have it often and it's broiled, baked and poached in the usual ways, it can get to be old hat. I love the stuff just about anyway it's made, but the other day thought to try a variation on my usual method.

Bake/broil being easy and relatively odor free is one of my favorite methods and usually I butter saute finely chooped vegetables - a carrot, a half an onion, a rib of celery and some herbs - whatever I have really - and coat the fillet with that, a little fresh squeezed lemon juice and maybe a bit of butter, bake it Canadian Method (ten minutes to the inch or less- never more) and then flash broil it for a moment to brown up the coating.

This method is foolproof, but I wanted to do something else and I had a box of mushrooms and so ... did the following. I sauteed finely chopped mushrooms, finely chopped shallots, a little chopped celery, salt and pepper in butter and oil until everything softened and the mushrooms had given up their water and dried out. This is pretty much just a duxelles. I let that mixture cool and mixed in some Helman's Mayo and pasted the fillet with this, squeezed on the lemon juice, a few pats of butter and baked it with a flash broil (about one minute) at the end.

It makes an elegant and unexpected nice piece o' fish.

Salmon Fillet - Center cut 1,1/2lb
Mushrooms, Fresh. 5-7 medium to large, finely chopped
Shallots, 2 or 3 medium size, finely chopped
Dry Vermouth or white wine, three ounces
Parsley, 12 stems, finely chopped, stems and leaves
Lemon - 1
Butter - 2 to 4 Tblsp
Oil - P-nut - amount equal to butter
Salt and Pepper
Mayo - 1/4 to 1/2 cup
Butter

Heat oven to 350 degrees
Place fish on foil on a baking sheet and fold foil up to make smaller baking vessel. This keeps everything together and makes clean up really easy. It also prevents the juices from spreading out and burning.
Make the Duxelles by sauteeing the mushrooms and shallots together in the oil and butter. Add the Parsley when the mushrooms have given up their liquid but before they are completely cooked.
Add salt and pepper to taste.
Adding a couple of ounces of Dry Vermouth or white wine at this point and cooking it off will do no harm.
Let saute together for a minute or two and remove from heat and allow to cool. I put the pan on the down-draft ventilator on my otherwise irritating stove.
When cooled, stir in Mayo. This is to hold the vegetables together when the fish cooks. It almost disappears in the cooking process unless you use LOTS of mayo.
Spread the Mushroom/Mayo mixture all over the flesh side of the fish.
Squeeze a half lemon over this and dot with butter or p-nut oil.
Place in center of preheated oven for the recommended 10 minutes per inch or less Canadian cooking time.
For the last minute of cooking, switch the oven over to broil. This will color the mushroom topping.
Remove, give it a minute to calm down and with a spatch, cut into serving pieces and plate...