Step 1

Bring a medium pot of water to a boil.

Step 2

Meanwhile, purée spinach, cilantro, miso, garlic, grapeseed oil, sesame oil, and lemon juice in a blender until mixture is smooth and very green. Season with salt and pour pesto into a medium bowl.

Step 3

Cook noodles according to package directions. Drain and add to bowl with pesto. Add butter and toss until butter is melted and noodles are coated in sauce.

Step 4

Divide noodles between bowls and top with sesame seeds.

Step 5

Do Ahead: Pesto can be made 1 day ahead. Cover and chill. Color might darken slightly.