Adapted from a recipe from Restaurants Unlimited, Seattle

2 ounces Tanqueray No. 10 gin

1/2 ounce Cointreau

3/4 ounce fresh lemon juice

1/2 ounce simple syrup

4 very thin cucumber slices

Champagne

1 lemon twist, for garnish

Reserve 1 cucumber slice for garnish.  Shake the rest of the ingredients, except the champagne, over ice, and strain into a chilled Martini glass.  Top with the champagne and add the garnishes.