1 1/2 oz of grapefruit juice
4 oz of Champagne
1/2 oz of cointreau orange liqueur (or orange liqueur)
1/2 oz of marie brizard poire williams pear liqueur (or cranberry liqueur)
Rim a wine glass with grenadine and caster sugar. Shake all ingredients (except champagne) and strain into the glass. Add champagne, and serve.