Here's a classic Italian cocktail aptly named for the beautiful rainbows seen on many romantic afternoons from the Ristorante Covo dei Saraceni in Positano.
1 bottle chilled Prosecco
1/2 oz. dry gin
1/2 oz. Cointreau
1 oz. chilled pineapple juice
1 1/2 oz. chilled orange juice
1/2 oz. chilled grapefruit juice
1 whole strawberry
Chill a long fluted champagne glass a few hours in the refrigerator before preparing. When ready to serve, remove the glass and pour in juices, gin and a touch of Cointreau. Fill the rest of the glass with Prosecco. Gently stir, and drop a strawberry in the bottom of the glass.