Heat a large heavy bottomed pot over medium-high heat and add bacon. Cook, stirring occasionally until crisp, about 6-8 minutes.
Lower heat to medium-low and add sliced onion. Cook until beginning to soften, 7 minutes, stirring to prevent burning.
Return heat to medium heat and add 1/4 of the collard greens and 1 cup chicken stock. Scrape up any browned bits on the bottom of the pan and let the greens cook down a bit until you can fit more in the pan. Continue to add more greens until all are able to fit in the pan.
Cook, stirring occasionally until the greens are completely wilted down and have changed color to a dark green, about 25 minutes. Add more liquid if it has evaporated before the collards have cooked down.
Collard greens, especially those from the farm, can be really gritty! Make sure to wash well by plunging the greens into a large bowl of cold water and letting them sit for 30 seconds. Remove them from the water by pulling them straight up without disturbing any dirt that fell to the bottom of the bowl.