In a large non-stick skillet add bacon. Cook on medium-low heat, stirring occasionally until bacon fat renders and bacon is almost crisp but still meaty, about 10 minutes. Remove half of the bacon from the pan and set aside on a paper towel-lined plate or container.
Add onion, salt, sugar, and crushed red pepper to pan. Cook, stirring occasionally until onion begins to caramelize, about 2 minutes.
Stir in garlic. Add half of the turnip greens to the pan, turning them in the hot oil until slightly wilted. Add remaining turnip greens, turning them until just wilted.
Add vinegar and chicken stock. Cover and simmer 5 minutes.
Remove cover and simmer an additional 10 to 15 minutes or until turnip stems are fork tender.
Transfer turnip greens to a serving dish. Top with remaining crispy bacon. Serve warm.
