1. Heat oven to 350 degrees F.
2. Cook bacon in large deep skillet until crisp, about 10 minutes. Remove bacon to paper toweling to drain; crumble. Keep fat in skillet.
3. Trim hard white bases and wilted leaves from Belgian endive. Halve lengthwise. Heat bacon fat. Working in batches, brown endive on both sides, about 5 minutes per side. Place, cut side up, in 13 x 9 x 2-inch oven-to-table baking dish.
4. Add onion and oil to bacon fat in skillet; saute until onion browns slightly, 4 minutes. Add vinegar, sugar, wine, broth, salt and pepper. Bring to boiling. Pour over endive.
5. Bake, covered, in 350 degrees F oven 45 minutes, until endive is fork-tender. (Can be made morning of dinner; refrigerate. Let stand at room temperature, 30 minutes. Reheat in 350 degrees F oven, 20 minutes.) Sprinkle with parsley and reserved bacon.