Preparation

• Put the measured oil in the refrigerator while you prepare the basil. Bring a pot of water to a boil. Have a bowl of ice water ready. Blanch the basil leaves in the boiling water for about 10 seconds. Remove them quickly with a strainer and dunk in the ice water, swishing them around to be sure they’re all cold. Remove from the water and squeeze gently to remove the excess water.
• Roughly chop the basil and put it in a blender. Add the oil and 1/2 tsp. kosher salt; blend until the basil is puréed. The mixture will be very frothy. Let the purée settle for about 30 min. Strain through a cheesecloth- lined fine strainer, very gently pushing on the solids to extract the oil. Use immediately or refrigerate for up to a week. For the best flavor, let the oil come to room temperature before using.