This works reasonably well with kale also.
Using the dried red chili - if you leave the chili whole, it will be less hot than if you shred it and use the seeds. You can also discard the seeds and use only the flavorful skin.
Heat the oil, add the chili (and garlic if using it), cook until chili darkens. Add the asafoetida (if using), then immediately add the collards and stir to coat with oil. Add the water and salt, bring to a boil, simmer for around 40 minutes - you want the liquid to be almost completely gone. If the mix dries out before the collards are done, add a little more water
Separately saute the onion in oil or butter, and add to the cooked collards. Add red wine vinegar, adjust seasoning and serve.