3 cups (packed) kale leaves, rough stems removed and chopped
3 cups (packed) spinach leaves
4 oz. goat cheese, crumbled
Kosher salt and freshly ground black pepper, to taste
Bring a large pot of water to a boil. Cook the pasta al dente according to package directions.
Meanwhile, heat the olive oil and butter in a large skillet over medium-heat, until the butter is melted and the oil just begins to shimmer. Add the garlic and onion and cook, stirring occasionally, until just softened, about 2-3 minutes.
When the pasta has about two minutes to go, add the kale to the skillet, followed by the spinach, and stir constantly until the greens just begin to wilt. The greens will continue to cook from the heat of the pasta, so be careful not to overcook.
Drain the pasta, then return the it to the pot (off of the heat). Pour the greens mixture over the pasta, add the goat cheese and Parmesan, and stir to combine. Serve warm.