For the tartar sauce, in a medium bowl, mix all ingredients and set aside. For the Cajun Beer-Battered Oyster Mushrooms, in a large bowl, mix flour, baking powder, paprika, cayenne, pepper, cumin, ...
Pulse for a few seconds until still slightly chunky. Put the trout onto a large roasting tray along with the halved lemons and par boiled potatoes. Put a couple of spoonfuls of the salsa verde ...