Preparation

To make pesto in a mortar

• Put 1 cup of the basil in a mortar and pound and grind with the pestle until broken down. Continue adding basil to the mortar, 1 cup at a time, until all of the basil is broken down nearly to a paste. Add the pine nuts, garlic, 1/2 tsp. salt, and 1/8 tsp. pepper and continue to mash until completely broken down. Moving the pestle in a circular motion, gradually mix in the oil and then the cheese. Season to taste with more salt and pepper.

To make pesto in a food processor

• Pulse the basil, pine nuts, garlic, 1/2 tsp. salt, and 1/8 tsp. pepper in a food processor until finely chopped. With the motor running, slowly pour the olive oil into the feed tube and process, stopping to scrape the sides of the bowl as needed, until the mixture forms a thick paste. Transfer to a medium bowl and stir in the Parmigiano. Season to taste with more salt and pepper.

• To store: You can store pesto in an airtight container in the refrigerator for up to 1 week, or in the freezer for up to 3 months. To refrigerate, transfer the pesto to an airtight container and pour enough oil over it to create a thin layer. This will prevent the pesto from oxidizing and changing color. To freeze, omit the oil layer and portion the pesto into small plastic freezer bags or ice cube trays so you can defrost only as much as you’ll use at one time. If using ice cube trays, freeze until solid, and then transfer the cubes to a plastic freezer bag for storage. Defrost overnight in the refrigerator.

A sauce this versatile (and delicious) won’t be sitting in your freezer for long. Here are some easy ideas for how to use it. Defrost the pesto and:

• Toss with hot pasta
• Stir into vegetable soup
• Dress a cold potato or pasta salad
• Toss with grilled zucchini and summer squash and topwith shavings of ­Parmigiano Reggiano.
• Serve with grilled lamb.
• Spread on sliced ripe freshtomatoes, top with breadcrumbs, and slide ­under the broiler to heat.
• Mix a couple of tablespoons with best-quality extra-virgin olive oil and use as a dip for bread.
• Spread between vegetable layers in a gratin.
• Use as a filling with tomato and ricotta for a vege­table lasagna.
• Serve with fish, as in Roasted Cod with Basil Pesto & Garlic Breadcrumbs