There are three things I love about this cocktail: It has gin in it (always a good thing), it takes less than a minute to make (ditto) and it doubles as dessert. What's not to love? This concoction feels granitalike to me, granita being -- as you may know -- a sort of slushy Italian dessert usually made from water, sugar and fruit or other flavorings. Obviously, this isn't that. In fact, I cheat completely, beginning with a pint of good-quality sorbet and then simply adding the other ingredients, two of which contain alcohol. I use lemon sorbet because I want this drink to be tart as well as sweet, something that's crisp and refreshing, a drink that could serve as something of a digestif after dinner or a Bloody Mary alternative on a Sunday morning. Gin is my booze of choice (though you could use vodka, tequila or any other white alcohol), as it gives the cocktail a slightly herbal, aromatic flavor that marries beautifully with the crackling dry and fizzy Prosecco I add at the end. The easiest way to whip this up is in a blender, although a food processor will work in a pinch. Just put in the sorbet and gin, and puree until smooth. Divide the nectar among glasses (champagne flutes are nice) and top with the bubbly and a mint leaf or two. Call it a cocktail, a digestif or a dessert -- in any case, it's good stuff. Potent. Easy. Like I said, what's not to love? GROWN-UP GRANITA Time: About 5 minutes 1 pint lemon sorbet 1/4 to 1/2 cup gin 1/2 cup dry Prosecco 6 to 8 fresh mint leaves for garnish. Put the sorbet and gin in a food processor or blender and blend until well combined but still slushy. Pour into champagne flutes, top with Prosecco, garnish with mint leaves and serve immediately. Yield: 4 servings. 