- 1 cup packed fresh basil leaves (about 2 bunches)
- 1/2 cup olive oil (preferably extra-virgin)
- 6 tablespoons freshly grated Pecorino Romano cheese (about 1 ounce)
- 6 tablespoons freshly grated Parmesan cheese (about 1 ounce)
- 1/4 cup pine nuts, toasted
- 1 1/2 teaspoons minced garlic
- 2 medium russet potatoes (about 3/4 pound), peeled, cut into 1/2-inch cubes
- 6 ounces green beans, trimmed, cut into 3-inch lengths
- 1 pound trenette
- Additional freshly grated Pecorino Romano cheese
- 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.