Remove the white ribs from the centers of the collard leaves. Stack the leaves on top of each other and slice into 1-inch pieces. Thoroughly wash the greens (I soak them and continue to change the water until no dirt or sand remains). Set aside.
Heat the olive oil in a Dutch oven over medium heat. Add the onions and cook until translucent, about 5 minutes. Pour in the broth and use a wooden spoon to scrape up any brown bits. Stir in the soy sauce, pepper, garlic powder and salt. Bring to a low boil. Add the greens and reduce the heat to a very low simmer. Cover and cook, stirring occasionally, for 30 minutes. Stir in the cider vinegar and simmer an additional 15 minutes.
Serve with hot pepper vinegar if desired.
Recipe courtesy of Katie Lee