1. Preheat oven to 400 degree F. In a skillet cook bacon over medium heat until crisp. Remove bacon. Drain, reserving 1 tablespoon drippings in skillet. Crumble bacon; set aside.
2. To prepare fennel, cut off and discard upper stalks of fennel. Remove any wilted outer layers and cut a thin slice from the fennel base. Wash fennel and cut in half lengthwise; remove core. Cut crosswise into very thin slices.
3. Add fennel and garlic to drippings in skillet. Cook over medium heat about 10 minutes until fennel is just tender and begins to brown, stirring occasionally. Remove from heat. Add mayonnaise, sour cream, blue cheese, bacon, and peppercorns to fennel; mix well. Divide mixture between two 16-ounce oven-proof crocks, souffle dishes, or other oven-proof dishes. In a small bowl combine Parmesan cheese and bread crumbs; top mixture in each crock with Parmesan mixture.
4. Bake, uncovered, 15 minutes, or until just heated through and tops are light brown. Do not overbake. Serve with radishes and/or Belgian endive leaves. Makes 6 to 8 servings.