Cut the stems into desired lengths. I like to use about an inch length. Slice them smaller if you're going to use them on bowls, leave them longer for snacking.
In a saucepan, combine the vinegar, water, sugar, garlic, bay leaves, red chili pepper and salt. Bring to boil and add the stems. Cook for 2 minutes.
Turn off the heat and let the stems and brine come to room temperature.
Pour into a glass jar with a plastic lid and store in the refrigerator. These will keep for a month in the fridge.
Notes
Note - the nutrition info on this is not correct. I had to use a bunch of collard greens, it wouldn't work at all with stems. The information is for the whole bunch, not just the stems. This will also work with other stems like kale stems or Swiss chard stems. It's a great all purpose pickle brine also!