Heat the 3 tablespoons of butter in a medium skillet, add the mushroom stems and saute over moderate heat, stirring, about 5 minutes or till most of their liquid has evaporated. Add the onion, bell pepper, celery, garlic, thyme and rosemary, reduce heat, cover, and simmer about 15 minutes, till vegetables are soft and liquid has evaporated. Preheat oven to 350. Place the meats in a large mixing bowl, add the sauteed vegetables and mix lightly. Add the mustard, ketchup, Worcestershire, Tabasco, salt and pepper to taste, eggs and breadcrumbs, and mix with hands till blended thoroughly. Shape the mixture into a firm, thick oval loaf, place in a shallow baking or gratin dish, drape bacon over the top, and bake 1 hour. Remove the bacon strips and continue baking 20 - 30 minutes longer, depending on how thick the loaf is and how crusty you want the exterior to be. Shortly before the meat loaf is removed from the oven, heat the 2 tablespoons of butter in a small skillet, add the reserved mushroom caps and saute, stirring, 2 minutes or till nicely glazed. Transfer the meat loaf to a large serving platter, arrange olives over the top and garnish the edges with the mushroom caps. Recipe by: Town and Country Magazine / Gails Recipe Swap Posted to MC-Recipe Digest V1 #886 by Dianne Larson Ward on Nov 07, 1997