Trenette al Pesto with Green Beans and Potatoes

Bring at least 5 L of water to a rolling boil in a large pot. Salt generously — the water should taste like mild seawater.

Toast pine nuts in a dry skillet over medium heat, stirring constantly, until golden, 2–3 min. Spread on a plate to cool completely.

Peel the potatoes and cut into 1.5 cm cubes. Trim green beans and cut in half.

Blend basil, cooled pine nuts, garlic, and a pinch of salt in a food processor to a coarse paste, about 20 seconds. Add Parmigiano and Pecorino; pulse 5 times. With the motor running, slowly stream in the olive oil until emulsified. Taste and adjust salt.

Add potato cubes to the boiling water. Cook 5 min.

Add trenette to the pot and cook according to package directions, targeting 1 min under al dente.

In the final 5 min of pasta cooking, add the green beans to the pot.

Before draining, ladle out 120 ml of the starchy cooking water and set aside.

Drain pasta, potatoes, and beans together through a colander.

Transfer everything to a large warm bowl. Spoon the pesto over and toss well, adding the reserved cooking water a splash at a time until the pesto forms a glossy, cohesive coating.

Serve immediately in warm bowls. Pass extra grated Parmigiano at the table.