Trofie al Pesto Genovese

Wash the basil gently and dry it completely on a cloth; water is pesto’s first enemy, heat the second.

Pound garlic with a few grains of coarse salt in the mortar to a cream. Add pine nuts; pound to a paste.

Add the basil in handfuls with a pinch of salt, crushing against the walls with a rotating wrist rather than smashing, until the leaves release a bright green liquor.

Work in both cheeses, then the oil in a thin stream, stirring with the pestle until you have a dense, fragrant cream. (Food processor truce: pulse briefly with chilled blade and bowl.)

Boil the potatoes in well-salted water for 5 minutes; add the trofie and green beans together and cook until the pasta is al dente.

Reserve a cup of cooking water, drain, and return everything to the warm (not hot) pot off the heat.

Fold in the pesto, loosening with splashes of the starchy water until every twist is coated in pale green cream. Serve immediately.