Shuck the corn and place on the grill to cook.

Meanwhile, slice the avocado open and pit it. Mash half of the avocado. Add in the chopped tomato and red onion. Chop the remaining 1/2 avocado, and fold into the mashed avocado. Add in the fresh lemon juice, a drizzle of olive oil, and sea salt to taste. Mix together well.

Once the corn is done grilling, transfer to a serving dish. Smash the guacamole mixture evenly around the up sides of the corn.

Enjoy immediately!