Slice the avocado around the middle, remove the stem and pit. Scoop the avocado out and mash it in a small bowl. Add the lemon juice, salt and pepper to taste.
I had an ear of leftover corn I'd boiled the night before, so I just cut the corn from the cob, and put it in a skillet until it was slightly browned.
Then toast a slice of whole grain bread. Put the slice of Havarti on top, melt it in the microwave for about 20 to 25 seconds, (or the toaster oven if you want to wait - personally I hate waiting) pile the avocado on top, then top with the roasted corn. Sprinkle with Tajin and enjoy!