4 tablespoons of Irish Whiskey
1 teaspoon of sugar or Splenda
Strong black coffee
Heavy cream very lightly whipped, just until it thickens slightly
1 teaspoon Creme de Menthe (optional)
Pour the whiskey into a warmed glass or mug. Add the sugar. Fill the glass to an inch from the top with hot coffee. Holding a teaspoon bowl-side-up over the drink, pour the thickened cream gently on the spoon and onto the top of the coffee/whiskey/sugar. (The result should look very much like a Pint of Guinness. A rich white head over a black liquid...)
For a festive look, drizzle the Creme de Menthe in a shamrock design on the top of the cream. This is a very precise operation and practice makes perfect.
Enjoy in moderation.