Remove stems and thick ribs from greens. In large saucepan of boiling water immerse greens, one-fourth at a time, for 30 seconds. Remove greens with tongs to colander. Rinse under cold running water; cool. Coarsely chop.
In 4-quart Dutch oven heat oil over medium-high heat. Add ham, garlic, and jalapeno; cook and stir 1 minute. Add broth and brown sugar; stir to dissolve sugar. Add greens and black pepper; cook and stir until heated through. Serve immediately; sprinkle with vinegar. Makes 10 (3/4-cup) servings.