Prepare ice cream machine according to the manufacturer’s instructions. Be sure to freeze the bowl ahead of time if required!
Peel and dice the mango.
Combine the mango and sugar in a large bowl, and let sit for one hour.
Blend together the mango-sugar mixture and tequila in a blender or food processor, or with an immersion blender. If the puree is too thick to blend completely smooth, add water 1 tablespoon at a time until you achieve the preferred texture.
Place a clean, dry egg in the base to test the sugar ratio. Because mango is a fibrous fruit, it will likely be viscous enough to stay afloat. If not, blend in additional sugar 1 tablespoon at a time until the egg floats at the top.
Chill in the refrigerator for two hours or over an ice bath for one hour. For an ice bath, nest your bowl of sorbet base in a bowl of ice and stir every 10 minutes for an hour, to chill the mixture evenly.
Churn according to the manufacturer’s instructions.