Rinse the kale leaves and pat dry, stripping out the tough center ribs. Add the leaves to the blender first.
Pour the almond milk over the kale. This helps the leaves break down instead of shredding into stringy bits.
Blend the kale and almond milk on high for 20 to 30 seconds until mostly smooth, with only tiny flecks left.
Add the avocado, frozen banana, lime juice, honey, and salt to the blender.
Blend for 45 to 60 seconds until fully smooth and creamy, stopping once to scrape down the sides.
Add the ice cubes and blend another 15 to 20 seconds until the smoothie turns thick and frosty.
Taste and adjust. Add more lime juice for brightness or another small drizzle of honey if the kale still tastes sharp.
Pour into two glasses and serve right away, while it's still cold and thick.