Besides being the title of that other Scottish film--the one starring Liam Neeson and Jessica Lange, not Mel Gibson--the name Rob Roy also represents the scotch version of the Manhattan. Essentially, you follow the same steps. In a mixing glass, over ice, pour 1 ½ oz. scotch (your preference), then either sweet or dry vermouth. Mix and strain into either a martini glass or an 8-oz. tumbler if you're drinking it on the rocks. If you've chosen to use dry vermouth, garnish with a lemon twist. For sweet vermouth, use a cherry.