Preparation:
Finely grind basil, oil, 6 tablespoons each Romano and Parmesan cheeses, toasted pine nuts and minced garlic in processor. Season pesto to taste with salt and pepper. (Pesto can be prepared 2 days ahead. Press plastic wrap onto surface of pesto and refrigerate.)
Cook potatoes in large pot of boiling salted water until just tender, about 5 minutes. Using slotted spoon, transfer potatoes to large bowl. Add green beans to same pot and cook until crisp-tender, about 3 minutes. Using slotted spoon, transfer to bowl with potatoes. Cook pasta in same pot until tender but still firm to bite. Drain, reserving 1/2 cup cooking liquid. Transfer pasta to bowl with potatoes and green beans.
Whisk reserved 1/2 cup cooking liquid into pesto. Add pesto to pasta mixture and toss thoroughly to coat. Transfer pasta to large platter. Serve, passing additional Pecorino Romano separately. |