Cook sweet corn on the cob by boiling for 4–5 minutes until tender, then cut kernels off the cob.

Chop cucumber into bite-sized pieces, dice red onion finely, and chop cilantro if using.

In a large bowl, combine sweet corn, cucumber, diced red onion, and chopped cilantro. Gently stir to mix.

Squeeze lime juice over the mixture, add salt and pepper, and toss everything together thoroughly.

Serve immediately or store in an airtight container in the fridge for up to 48 hours.