Use this zest to decorate our Frozen Lemon Mousse.
Remove zest from lemons with a vegetable peeler, keeping pieces long. Remove white pith using a paring knife. Cut into a fine julienne using a very sharp knife. Place julienned zest in a small bowl; cover with boiling water. Let stand 30 minutes; drain.
Bring sugar and the cool water to a boil in a small saucepan over medium-high heat. When sugar is completely dissolved, add julienned zest, reduce heat to medium low, and cook 10 minutes. Remove from heat, cover, and let stand overnight.