Steam the corn. Add water to a large pan to fill an inch high. Once the water is boiling place a steamer basket in the pan with the corn. Cover and steam for 10 minutes.
Slice off the corn kernels and place in a bowl with the diced tomatoes, avocado, red onion, cilantro and lime juice.
Season with cumin, salt and pepper.
Top with tajin if desired.
Taste and adjust accordingly.
