Cocktail Time!

Not the book by P. G. Wodehouse (nor Sir Raymond Bastable, nor Cosmo Wisdom, if it comes to that), as delicious and mildly intoxicating as that book is.

Instead, I would like you to apply your minds to the following conundrum: what are the ingredients of the cocktail known as a Port Flip?

Porto Flip
Not to be confused with its cousin the Porto Flip, shown above.

A brace of hints: the port flip has three ingredients, and this is not a trick question.

What do you think?