The key to this simple recipe is that someone needs to catch the fish, in season, adjacent the where you will clean and cook it.
Catch a brook trout. Light the grill and get it to medium. Almost immediately, clean the fish and slice a shallot. Lightly salt and pepper the cavity and then stuff it with shallots and 1 Tbsp butter. Place it in a metal baking pan and bake it on the grill for ten or 15 minutes until done. Eat it immediately. It would be hard to find something that tastes better than this.
But remember - catch it and eat it - the whole process should take less than an hour...