Melt half the butter in a small pan and sauté mushrooms and garlic. Add half the herb mixture, lemon juice, salt and pepper. Stuff the trout with this mixture. Butter pieces of foil, and lay one trout on each. Sprinkle with the remaining herbs, then dot with the remaining butter.Season with salt and pepper and wrap up the foil. Bake at 350 degrees F for 30 to 40 minutes. Fish should be firm and should flake easily with a fork. Serves 4.