Step 1

Cook spaghetti; drain, reserving ½ cup pasta cooking liquid.

Step 2

Meanwhile, heat butter in a large skillet over medium heat. Cook anchovies and garlic, stirring often, until anchovies are broken down and garlic is soft, about 4 minutes.

Step 3

Add tomatoes; season with salt and pepper and cook, stirring occasionally, until falling apart, 8–10 minutes.

Step 4

Toss in pasta and reserved pasta cooking liquid; cook until sauce coats pasta, about 2 minutes. Toss in herbs.