Wash and dry the basil leaves and crush in a mortar with peeled garlic, pine nuts and a pinch of salt
Add oil in a steady stream while crushing with the pestle until a smooth pesto sauce is obtained. Pesto can also be made in a blender: do not overprocess and use quick pulses, so that the pesto does not heat up
Pour pesto in a bowl and combine with half the grated Parmigiano and Pecorino cheeses
Dice the potato and cut the green beans into pieces. Boil the linguine, diced potato and green beans in plenty of salted water for about 10 minutes
Drain, combine with pesto and a few tablespoons of cooking water and serve immediately with the remaining grated Parmigiano
