Wash and scrub the sweet potatoes. Slice crosswise into rounds. Place potato rounds into a bowl and cover with cold water. Allow the potatoes to soak for at least 20 minutes and up to several hours.
Preheat oven to 450 degrees. Remove potatoes from the water and pat dry with paper towels. Place potatoes in a single layer on a baking sheet and drizzle generously with olive oil. Sprinkle with salt and pepper. Roast the potatoes for 20 minutes. Remove from oven, flip, and roast another 10-15 minutes until crispy.
Arrange the potato rounds on a bed of kale along with remaining salad ingredients.
Make the dressing: Process all ingredients in a blender until smooth and pale green in color. Store in an airtight container in the fridge.