Bitters Lime And Tonic - cooking recipe

Ingredients

crushed ice
30 drops angostura aromatic bitters (from a 500 ml bottle-5 drops per each drink)
2 limes
1 1/2 liters tonic water
mint sprig

Preparation

Half fill tall glasses with ice.
Top each with 5 drops of bitters and a good squeeze of lime juice.
Slice remaining lime.
Fill each with tonic water and top with lime slice and fresh mint leaves.