Opal is biting quite strong cocktail at 1.7 standard drinks. Shaken with 45ml gin bulldog and 15ml orange liqueur with 50ml orange juice as well as 100ml ice and best served with fish and seafood dishes. Just add ice to shaker then add all ingredients and shake well. Strain into glass and garnish with grenadine and curacao to make opal pattern and served in a saucer glass cold.