Thoroughly wash the potatoes and cut them into 1 inch cubes. Shred or chop lettuce.
Arrange potatoes on a baking sheet lined with parchment paper; sprinkle with sea salt and black pepper. Bake for 25-30 minutes, turning once half way through.
While potatoes are cooking, cook rice according to package instructions.
Fluff rice with a fork and fold in corn. Halve tomatoes, chop onion and avocado, and slice lime into wedges.
Spoon the rice mix into 1/4 of a large serving bowl or platter, then add remaining ingredients as pictured.
Add all dressing ingredients to a blender and blend until mixture is well combined and thin; add more water if needed. Drizzle over salad.