Remove most of husk from corn leaving only the thin pale green husk layer. Peel back husk removing silk; replace husk. Roast corn turning as needed (about every 2 minutes) until corn is golden brown, approximately 10 minutes. Remove from grill.
Stack tortillas in foil; sprinkle with a little water from fingertips. Close foil and place on grill to warm.
Check the garlic - it's done when yields to soft pressure and is nicely browned. Squeeze out roasted garlic and spread on warmed tortilla. Fill tortilla with corn mixture. Add slices of avocado and garnish with tomatoes.