Recipe for "Collard Greens" from "A New Turn in the South: Southern Flavors Reinvented for your Kitchen" by Hugh Acheson.
I made 1/2 the recipe. I used about 1.5 pounds collard greens (instead of the 4 pounds in the original recipe), but I did use one whole ham hock because ham hocks are difficult to split. I was able to find the young collard greens which were recommended in the recipe (though mature collard greens are fine to use too--they may just take longer to cook), and I cooked the greens for the recommended 2 hours.
The ham hocks are salty, so this dish doesn't need much added salt. Also even though the hock is mostly bone, skin, and fat, at the end of cooking, you can carve pieces of meat off the hock, dice it, and add it to the greens. The meat adds a salty, smoked ham flavor to the greens.
I also used water instead of the chicken stock, since I didn't have any homemade and didn't want to buy any $10 artisanal chicken stock at the farmer's market for this, and Michael Ruhlman suggests in "Ruhlman's Twenty: 20 Techniques, 100 Recipes, A Cook's Manifesto" that using water is better then using store bought stock (because stock has off flavors) when the other cooking ingredients will give off enough flavor to make a impromptu stock. For this recipe, he was right. The smoked ham hock, the onion, and vinegar (1 used 1 entire small onion) gave off enough flavor to make a savory meaty "potlikker" for the greens.