If using whole collards, wash thoroughly and remove the whole leaves from the main stem. I find that using a sharp knife makes this easy just to slice along the stem. Tear each leaf into smaller pieces about 2-3 inches in size. You can discard pieces that have stems that are too large.
If using bagged collards, remove them from the bag and wash thoroughly, removing any pieces that have large stems.
Into a large stock pot, heat oil over medium-high heat. Add onion and cook until they have softened. Then add garlic and cook for just a minute or two.
Add water, vinegar, vegetable base, chicken base, and red pepper flakes to the pot and heat until everything has fully mixed. Be sure to taste the broth and add extra salt, red pepper flakes, or vinegar to taste.
Bring everything to a simmer and then add collards. Cook on medium/medium-low heat until collards become tender and just al denté.
Remove from heat and serve, or store in a container with the broth (these actually are better leftover!)
