1. All you have to do is take a small bowl and mix all the ingredients in with the butter and cream together. Add more lemon juice or zest to taste.
2. Cut a piece of wax or parchment paper into a rectangle and spread the mixture in a strip along the width of the paper. Roll into a rough cylinder. Twist the ends of the paper and refrigerate or freeze. Slice to use.
You can freeze these butters for 2-3 months.