Instructions: 

1. Preheat the oven to 350 degrees F.
2. Prepare the kale by washing it thoroughly. 
3. Use a knife to cut off the stems of the kale. You can then chop or tear the kale leaves into bite-size pieces; they do not need to be perfect pieces and will all range in size but inevitably will shrink in the oven. 
4. In a large bowl, add the kale, balsamic vinegar, salt, and oil if using.
5. Lightly massage the kale, salt, and balsamic vinegar and oil if using, ensuring all of the kale is evenly coated with the mixture.
6. Place the kale in a single layer on a baking sheet with parchment paper.
7. Place the baking sheet in the oven for 10 minutes. Check the kale after 10 minutes to see if most of the pieces are crispy. They will become even more crispy when cooled. If some of the pieces are not crispy, remove the crispy kale pieces and place the baking sheet back in the oven for 3-minute intervals, checking to make sure they do not burn. 
8. Remove from the oven and enjoy warm or once cooled!

Recipe Courtesy of jaz boler