In a high-speed blender or food processor add mango, orange juice, lime juice and optional sugar. Blend until smooth. If you are not using right away, store it in the refrigerator.

Using a margarita or short cocktail glass, wet the rim (you can use water or lime juice) of the glass and dip into kosher salt.

In a cocktail shaker, add ice, tequila, mango puree, lime juice, triple sec and cilantro. Shake until combined and cold.

Pour into the prepared glass and top with seltzer water. Garnish with a lime slice if desired.