2 oz bourbon
8 sprigs of mint
1 tsp of sugar

Muddle mint and sugar in mixing glass. Add shaved ice and bourbon. Shake until frosted and pour all into rocks glass full of crushed or shaved ice. Garnish with a mint sprig.

See also:
http://usumcasane.tumblr.com/post/555114642 for crushed-mint-in-the-glass style
and
http://www.foodnetwork.com/recipes/sara-moulton/the-perfect-mint... for extracting mint beforehand.