2 cups sparkling seltzer water (be sure it says Sparkling Seltzer Water and not club soda or tonic water...seltzer water contains only carbonated water)
1 cup ice
Directions
Add the first 3 ingredients to a large glass, stir to combine.
Add ice to 2 glasses, equally divide mixture between glasses and top each off with one cup sparkling seltzer water.
Add a few half slices of lime to each glass, if desired.