Ingredients:

  Amount  Measure       Ingredient -- Preparation Method
--------  ------------  --------------------------------
   1      cup           packed fresh basil leaves -- (2 bunches)
   1 1/2  cups          olive oil -- (preferably
                        -- extra-virgin)
   6      tablespoons   pecorino romano cheese -- freshly grated
   6      tablespoons   freshly grated parmesan cheese -- (1-oz)
     1/4  cup           pine nuts -- toasted
   1 1/2  teaspoons     minced garlic
   2      medium        russet potatoes -- peeled, cut in 1/2"
                        -- cubes
   6      ounces        green beans -- trimmed, cut in
                        -- 3"lengths
   1      pound         trenette pasta or linguine
                        additional freshly grated pecorino
                        romano cheese

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.