In a bread pan or container similar, combine frozen margarita concentrate, water, tequila and sugar. Stir until well combined then place in a freezer overnight.
When ready to serve, rim a chilled glass with coarse sea salt. Scrape the frozen contents of the bread pan into the glass then garnish with a lime wheels, if desired.
Notes
It’s easy to rim a glass with salt! Just wet the rim of a glass with a fresh lemon wedge then dip the glass in a plate of coarse sea salt.