Bring a pot of salted water to a boil for your pasta. Cook it according to the directions and before draining, reserve about 1 cup of the starchy water.
While the water is boiling, heat a large skillet or pot over medium heat. Add 2 tablespoons of the butter. Once melted, stir in the pepper. Toast for about 60 seconds. Add in the chopped kale and stir. Add in 3/4 of the water and bring the mixture to a simmer. Add in the remaining butter and the pasta and toss it together (the kale will continue to wilt with the hot pasta). Reduce the heat to low and stir in the parmesan and pecorino. Toss until the cheese is melted and becomes somewhat of a sauce with the water and the pasta.
Serve immediately with extra parmesan shavings and freshly cracked black pepper.