1. prepare margarita mix: Stir tequila, grand lime juice, lime zest, Marnier and sugar in a glass pitcher until sugar dissolves. Cover and steep for at least 2 hours in the refrigerator (24 hours max). Strain into another pitcher.
2. prepare and serve: Scrape rims of chilled cocktail glasses with lime slices, then turn glasses to other side in coarse salt. Bring margaritas to table on ice cubes in glasses with salt rims.
*approx. 1/2 bottle 1 cup = 1 us cup = 240 ml.
-Adapted from “Mexican Kitchen” by Rick Bayless.