Photo from tvanhoosear

It's actually relatively simple to create your own Shamrock Shake.  Just get some whole milk, good vanilla ice cream, peppermint extract, and green food coloring.

From The Daily Meal/FOX News:

Step 1: Perfect the Vanilla Milkshake

If you can make a vanilla milkshake, you’re more than prepared to make a Shamrock Shake at home. All you need is vanilla ice cream and milk to make the base.

Step 2: Add Peppermint Extract

Peppermint extract goes a long way, remember, so don’t overdo it in your vanilla milkshake. When adding the ingredients to a blender, add the peppermint extract for a creamy mint treat. Our best proportions for a shamrock shake:

2 cups vanilla ice cream

¾ cup of milk

¾ teaspoon peppermint extract

Step 3: Add Food Coloring

As the final touch to your Shamrock Shake, add up to eight drops of green food coloring. (Remember, like peppermint extract, it’s a potent ingredient — so don’t overdo it.) Blend all ingredients on high speed until smooth, and you’re good to go. (Whipped cream and a maraschino cherry not included.)

Read more: http://www.foxnews.com/leisure/2013/03/06/diy-mcdonald-shamrock-shake/#ixzz2MwpAfWww