high-protein feta mac and cheese

0 Bring a large pot of salted water to a boil. Add the pasta and cook according to package directions for al dente. Drain.
1 Meanwhile, add the cottage cheese, milk, feta, and cornstarch to a blender. Blend until smooth.
2 Heat the butter and several grinds black pepper in the now-empty pasta pot over medium-low heat. Add the sauce and season with salt, seasonings of choice, and more black pepper to taste. 
3 Cook until gently bubbling and beginning to thicken, 5 to 8 minutes. (Do not increase the heat!) Remove from heat, wait for the bubbling to stop, and then stir in the pasta.