Here is a more traditional recipe from Gourmet Magazine:
½ pound sliced bacon, cut crosswide into fourths
3 medium red onions, chopped coarse (about 3 cups)
1 ¼ cups chicken broth
¼ cup cider vinegar
2 Tb firmly packed dark brown sugar, or to taste
½ tsp dried red pepper flakes, or to taste
4 pounds collard greens (preferably small leaves), coarse stems and ribs discarded and leaves and thin stems washed, drained, and chopped coarse
In a deep heavy kettle, cook the bacon in 2 batches over moderate heat until crisp and transfer to paper towels to drain. Pour off all but 3 tablespoons of drippings. Cook onions in the kettle with remaining drippings, stirring occasionally, until browned slightly and softened. Transfer onions with a slotted spoon to a bowl.
Add broth, vinegar, brown sugar, red pepper flakes, and about half of bacon to kettle, stirring until sugar is dissolved. Add about half of collards, tossing until wilted slightly, and add remaining collards, tossing until combined. Simmer collards, covered, 30 minutes. Stir in onions and simmer, covered, 30 minutes more, or until collards are very tender. Serve topped with remaining bacon.