Here’s the recipe from the most recent Cook’s Country, entitled Braised Hearty Greens.
4 TB butter
½ red onion, sliced thin
2½ lbs hearty greens (collard, kale, mustard, turnip), stemmed and chopped
1 C low-sodium chicken broth
1 TB brown sugar
½ tsp salt
¼ tsp cayenne pepper
2 TB cider vinegar
1. Simmer greens: melt 2 TB of butter in a large pot or dutch oven over medium heat. Cook onion until softened, about 5 minutes. Add half of greens (or all, if they fit), broth, sugar, salt and cayenne. Cover and cook until greens are beginning to wilt, about 1 minute. Stir in remaining greens (if needed), then cook, covered, stirring occasionally, over medium-low heat until completely tender, about 30 minutes.
2. Finish cooking: remove lid and cook over medium-high heat, stirring occasionally, until liquid is nearly evaporated, about 10 minutes. Off heat, stir in remaining butter and vinegar. Serve.