Heat the oil on high in a 4-quart slow cooker (crock pot). Add the onion and garlic, and cook until you prep the remaining ingredients.
Thoroughly wash the collards and chop coarsely.
Add the chopped collards and vegetable stock to the pot.
Season with salt and pepper.
Turn the heat setting to low, cover and cook for 6 hours until the collards are tender. (Alternately, you can make this recipe on top of the stove in about 30 minutes by sautéing everything and watching it closely.)
Just before serving, stir in the vinegar or Liquid Smoke.
Notes
Alternate Cooking Method:If you prefer your collards to be bright green and more chewy, as I do, sauté them on top of the stove.
Heat your oil in a large sauté pot, add the onions and cook until tender and transparent.
Add the garlic. Give it a stir.
Add the chopped collards, vegetable stock, salt and pepper, and cook over medium heat for about 15 minutes until the greens are still bright, but becoming soft.
Splash in the vinegar or liquid smoke, and serve hot.