Spaghetti with Tomato and Walnut Pesto

Preparation

1. Step 1

   Preheat oven to 350°F. Toast walnuts on a rimmed baking sheet, tossing once, until slightly darkened, 8–10 minutes. Let cool.

   Step 2

   Heat broiler. Toss tomatoes with 2 Tbsp. oil on a rimmed baking sheet; season with salt. Broil, tossing once, until tomatoes are blistered and have released some of their liquid, 5–7 minutes. Let cool.

   Step 3

   Pulse anchovies, garlic, lemon zest, red pepper flakes, and 1/2 oz. Parmesan in a food processor until finely ground. Add walnuts and half of tomatoes, then, with motor running, stream in 1/3 cup oil; process just until combined. Season with salt. Transfer pesto to a large bowl and stir in black pepper.

   Step 4

   Cook pasta in a large pot of boiling salted water, stirring occasionally, until al dente. Drain, reserving 1/2 cup pasta cooking liquid.

   Step 5

   Transfer pasta to bowl with pesto and add a splash of pasta cooking liquid. Toss, adding more cooking liquid as needed, until sauce coats pasta. Add basil and remaining tomatoes.

   Step 6

   Divide among bowls; top with more Parmesan and black pepper and drizzle with oil.

2. Do Ahead

   Step 7

   Pesto can be made 1 day ahead. Cover and chill.