Begin by cutting each ingredient into its respective size. Then, place them into a medium size bowl for mixing, except the romaine lettuce leaves.
On a separate plate, place the 4 leaves of romaine lettuce down first, followed by the bowl mixture of black beans, corn kernels, avocado oil, purple onion, and tomatoes.
Season with the 1/2 tsp of black pepper and 1/8 tsp of sea salt, and enjoy!