Separate the egg yolks and whites. Refrigerate the whites.
Add the egg yolks to a large bowl and beat with a electric hand mixer for several seconds. Add the sugar and continue mixing until the sugar is dissolved and the yolks are pale yellow and fluffy – about 1 to 2 minutes.
Add the bourbon and sherry (or liquors of your choice), then beat at low speed until well mixed. Add the milk, heavy cream and nutmeg, then beat at low speed until well mixed. Place the bowl in the refrigerator until ready to serve.
Just before serving, place the egg whites in a second large bowl and beat with an electric hand mixer until they form stiff peaks.
Gently fold the egg whites into the yolk mixture with a spatula, then gently whisk to smooth out the texture. Serve immediately.