This spinach pesto comes together in just minutes while the pasta cooks. It's quick, easy, and delicious — what more could you ask for out of a weeknight-friendly dinner recipe?
Bring a large pot of salted water to a boil over high heat. Cook the pasta according to the package directions, drain, and set aside.
In a blender or the bowl of a food processor, combine the spinach, oil, Parmesan, parsley, garlic, salt, and basil. Mix at medium speed until chopped finely. Melt the butter in the water. With a blender or processor running, gradually pour in the melted butter mixture until blended. Toss the pesto with the pasta. Sprinkle feta on top and serve.