Bring 3 quarts of water to a boil. Add a pinch of salt and lemon juice.

Add parsley for 20 seconds then immediately strain and drop into ice water to cool.

Strain parsley and put in blender with milk and blend until smooth.

Zest lemons into puree and reserve.

Prepare mashed potatoes. Mix in butter at room temperature.

Season with salt and pepper to taste and then mix in parsley puree.