Pour crème de menthe into a cordial glass. Take a teaspoon and touch the edge of the spoon to the inside of the glass, the round side up just at the surface of the crème de menthe layer. Gently pour the Irish cream onto the rounded spoon back forming a white layer above the green layer. Then repeat the process for the layer of orange or brandy.
The finished drink should be bands of green, white, and orange, like the Irish flag.