Ingredients

Equipment Needed

• •Large marble mortar and wooden pestle (traditional)
• •Food processor (acceptable alternative)
• •Large pot for pasta and vegetables
• •Salad spinner or clean kitchen towels

Instructions

1. 1

   Prepare the basil

   Wash the basil leaves gently and dry them completely. Wet basil darkens when pounded and produces an inferior pesto. Spread the leaves on clean kitchen towels and pat dry, or use a salad spinner. The leaves must be bone dry.

2. 2

   Begin the pesto

   In a large marble mortar, combine the garlic cloves and coarse salt. Pound with the wooden pestle in a circular, grinding motion until you have a smooth paste. The salt acts as an abrasive. Add the pine nuts and pound until they are incorporated into the paste. This takes patience.

   A food processor may be used if a mortar is unavailable. Pulse briefly; do not let the blade heat the basil. The texture will be different, less creamy and more uniform. The mortar produces something the machine cannot replicate.
3. 3

   Add the basil

   Add the basil leaves in small handfuls, pounding and grinding against the sides of the mortar with a rotating motion. Work each handful into the paste before adding more. The pounding bruises the leaves and releases their oils without heating them. This is why mortar pesto tastes different from blender pesto. Continue until all the basil is incorporated and you have a thick, bright green paste.

4. 4

   Add the cheeses

   Work in the grated Parmigiano-Reggiano and Pecorino, pounding gently to incorporate. The cheeses add body and salt. Taste. Adjust.

5. 5

   Add the oil

   Add the olive oil in a thin, steady stream while stirring with the pestle. The pesto should become creamy and emulsified. Transfer to a bowl and press plastic wrap directly onto the surface to prevent oxidation. The pesto can wait like this for an hour or two. It does not improve with time.

6. 6

   Cook the vegetables

   Bring a large pot of water to a vigorous boil. Salt it generously. Add the potato cubes first and cook for 5 minutes. They need a head start. Then add the green beans and cook together for another 5 minutes, until both vegetables are tender but not soft. They will finish cooking with the pasta.

7. 7

   Cook the pasta

   Add the trofie to the pot with the vegetables. Cook according to package directions for dried pasta, about 12 minutes, or 3 to 4 minutes for fresh. The pasta, potatoes, and beans cook together in the same water. This is how it is done in Liguria. Reserve one cup of the starchy cooking water before draining.

   The starch from the potatoes enriches the pasta water. This is not an accident. The Ligurians understood what they were doing.
8. 8

   Combine and serve

   Place the pesto in a large warmed serving bowl. Add two or three tablespoons of the hot pasta water and stir to loosen. Drain the pasta and vegetables and add them to the bowl. Toss gently but thoroughly until every twist of pasta is coated with the green sauce. Add more pasta water if needed to achieve a creamy consistency. The pesto should cling, not pool. Serve immediately in warmed bowls. Do not add cheese at the table. There is already enough in the pesto.

Chef Tips

• •Do not toast the pine nuts. Ligurian tradition keeps them raw. Toasting adds a different flavor that competes with the basil. Some Romans toast. They are wrong.
• •If using a food processor, chill the bowl and blade in the freezer for 20 minutes. This prevents the friction heat that turns pesto brown and bitter. Pulse in short bursts. Never let it run continuously.
• •The ratio of Parmigiano to Pecorino matters. Too much Pecorino makes the pesto aggressive. The traditional balance is roughly four parts Parmigiano to one part Pecorino. Fiore Sardo from Sardinia is most traditional; Romano is acceptable.
• •Pesto oxidizes quickly. If not using immediately, float a thin layer of olive oil on top and press plastic wrap directly onto the surface. It keeps for two days refrigerated, but fresh is always superior.

Advance Preparation

• •Pesto can be made several hours ahead and stored with plastic wrap pressed directly on the surface. It will darken slightly. This is unavoidable.
• •For longer storage, freeze pesto in ice cube trays, then transfer to freezer bags. Add the cheese only after thawing. Frozen pesto keeps three months but loses some vibrancy.
• •The potatoes and green beans must be cooked fresh with the pasta. There is no way around this.

Frequently Asked Questions

Nutrition Information

1 serving (about 370g)