Begin by preparing all your components before combining. Dice the tomato into pieces roughly the same size as your planned avocado cubes. Finely chop the red onion, seed and mince the jalapeno, chop the fresh cilantro, slice the scallions, and mince the garlic. Thoroughly drain the canned corn and rinse the black beans under cold running water until the water runs clear. Squeeze the juice from both limes into a small bowl and set aside. Finally, cut the avocados into 1/2-inch cubes—do this step last to prevent browning. Having everything prepped and ready ensures quick assembly and even flavor distribution.

In a large mixing bowl, combine the drained corn, rinsed black beans, diced tomato, chopped red onion, minced jalapeno, cilantro, scallions, garlic, sea salt, and ground cumin. Add the avocado cubes to the bowl. Using a wide spatula or large spoon, gently fold all ingredients together, being careful not to break up the avocado cubes. Pour in about half the lime juice, toss gently, and taste. Continue adding lime juice and adjusting the salt until the acidity and seasoning are balanced to your liking. Let the mixture rest at room temperature for 15 minutes before serving to allow the flavors to meld and the seasonings to distribute evenly throughout.