Place whole eggplant on grill, close lid and let char for 3-4 minutes, then turn and rotate until evenly charred on all sides. Turn off one side of the grill, and place charred eggplant off the flames. With thte lid closed, continue to cook for an additional 10-15 minutes until the eggplant feels soft and ultra squishy to the touch. Alternately, if you do not have a grill, you can roast the eggplant in your oven, but you will lose that lovely smoky flavor. 400 degrees, for 45-60 minutes until soft and collapsing on itself.
Set aside and let cool enough to handle, and cut in half.
Scrape the flesh into a sieve to drain, the flesh should pull away easily,
Let drain for an hour or so to lose the excess water. If you want to speed the process, I bet a nutmilk bag would do the trick, or some layered cheesecloth wrapped up and gently squeezed.
In a bowl, mix the eggplant, mayo, garlic and sea salt to taste. The eggplant should be so soft, that it mashes easily as you mix the ingredients, almost like pudding. Taste and adjust seasonings as you wish.