Active Time

　　30 min

　　Total Time

　　35 min

　　

Ingredients

Makes 6 main-course servings

　　1 lb spaghetti

　　1/3 cup olive oil

　　4 cups chopped scallions (from 4 bunches)

　　2 garlic cloves, finely chopped

　　1 teaspoon finely grated fresh lemon zest

　　3/4 teaspoon salt

　　1/2 teaspoon black pepper

　　1 oz finely grated Parmigiano-Reggiano (1/2 cup)

　　

Step 1

Cook spaghetti in a 6- to 8-quart pot of boiling salted water until al dente.

　　

Step 2

While pasta cooks, heat 3 tablespoons olive oil in a 12-inch heavy skillet over moderate heat until hot but not smoking, then cook scallions and garlic, stirring occasionally, until scallions are softened and garlic begins to turn golden, about 5 minutes.

　　

Step 3

Transfer scallion mixture to a blender and add zest, salt, pepper, remaining olive oil, and 1/2 cup pasta-cooking water, then purée until smooth. (Use caution when blending hot liquids.)

　　

Step 4

Drain pasta in a colander and return to pot.

　　

Step 5

Toss pasta with scallion purée, cheese, and salt and pepper to taste over moderate heat until pasta is well coated.