Cut the kernels off the cob and mix together with all the remaining ingredients. Keep covered and refrigerated.
The recipe for salsa should not be made a day in advance, as the avocado will turn brown.
Preheat grill or broiler.
Season chicken with olive oil, salt and pepper. Brush with lemon juice. Grill 10 to 15 minutes total on a hot grill, turning 3 times. Serve with Avocado Corn Salsa.