2 oz. Madre mezcal (adds a nice, smoky flavor!)
1 slice of orange or grapefruit for garnish
Cut a fresh lime in half and rim the glass with the lime. Roll the glass onto a small dish of tajin. Take the other lime half and squeeze the juice into the glass.
Pour mezcal into a glass. Fill the rest of the glass with ice. Top off with topo chico. Garnish with a slice of orange or grapefruit.