For 1 lb of pasta ( I like Fischiotti or Cellentani; Trenette are traditional; Spaghetti are great too)
About 2 cups of fresh basil leaves
1 tsp of salt
½ cup extra-virgin olive oil
small handful of pine nuts (pinoli)
2 cloves garlic, coarsely chopped
About ½ cup grated Parmigiano Reggiano
About ¼ cup grated Pecorino
2 potatoes, peeled and chopped into small dice, or thinly sliced, placed in a bowl of water
Place basil, salt, olive oil, pine nuts and garlic in blender. Process till you get a coarse paste (you don’t want it to be velvety smooth). Pour into a small bowl. Add the grated cheeses a little at the time, stirring till completely incorporated. Now you can leave it out for hours, till you’re ready to make the pasta (but, if storing overnight, refrigerate it, covered).
Place water for pasta to heat in large pot. When boiling, add salt, then the drained potatoes. Cook about 5 minutes. Then throw in the pasta, stir and cook till al dente, about 10 minutes (test it).
Drain pasta (save some of the water!), place in bowl. Pour a small ladleful of pasta water into prepared pesto, stir, then pour sauce over pasta and potatoes. Mix well.
Serve with extra grated cheese.
(Adapted from recipe for Pesto by Marcella Hazan)