Bring a large pot of water to a boil. Add fresh corn on the cob and blanch for 3-5 minutes until tender but crisp. Alternatively, grill for 10-15 minutes until lightly charred. Let cool and slice off the kernels.

In a mixing bowl, combine diced corn with diced avocado, and if using, add chopped tomatoes, red onion, and cilantro. Gently fold without mashing the avocado.

Squeeze lime juice over the mixture and gently toss to coat the ingredients. Be careful not to mash the avocado.

Serve immediately for the best experience. Store in the fridge without avocado for up to 24 hours; add the avocado and lime juice right before serving.