Tear or chop kale into small pieces and place in a large salad bowl.
Add olive oil, lemon, sea salt, and mustard to a small bowl, whisk to combine.
Pour dressing over the kale then use your hands to massage pieces between your fingers. Kale should turn a brighter green and become softer. Keep massaging for 2-4 minutes.
Use massaged kale as the base for your salad, then add desired toppings.