1. Cook bacon in a 12-inch cast-iron skillet over medium heat, turning occasionally, 8 to 10 minutes or until crisp. Remove bacon; drain, reserving 2 Tbsp. drippings in skillet. Coarsely chop bacon.
2. Add oil to hot drippings in skillet. Cook onion and sweet potato in hot oil and drippings over medium heat, stirring occasionally, 5 minutes. Add turnips; cook, stirring occasionally, 8 minutes.
3. Combine vinegar and 2 Tbsp. water. Add Brussels sprouts, garlic, and vinegar mixture to skillet. Cover and cook, stirring occasionally, 5 minutes or until vegetables are tender. Stir in bacon; add salt and pepper to taste.