How to Make It
In a small saucepan, combine the chopped mango with the mango nectar, honey and habanero chile. Bring to a simmer and cook over moderate heat, stirring occasionally, until the mango is very soft, about 10 minutes. Transfer to a food processor and puree until smooth. Strain the mango puree into a small bowl and let cool, about 30 minutes.
Wipe out the food processor. Add the cooled mango puree along with the butter, cilantro leaves and salt and puree until smooth. Scrape the mango butter into a small bowl, cover and refrigerate until chilled, about 30 minutes.
Light a grill or preheat a grill pan. Pull the corn husks down to the base of the stalks, leaving the husks attached. Discard the corn silk. Using butcher string, tie back the husks. Fill a large bowl with cold, salted water and submerge the corn for 10 minutes.
Drain the corn but don't pat dry. Grill the corn over moderate heat, turning occasionally, until tender and browned in spots, about 8 minutes. Transfer the corn to plates, spread with the mango-habanero butter and serve.