Bring an 8-quart stockpot of water to a boil over high heat. Season aggressively with kosher salt.
Once your water comes to a boil, add your pasta and give it a quick swirl with a wooden spoon. Cook pasta according to package directions. Drain, reserving 2 cups of pasta water.
While pasta is cooking, warm a 10- to 12-inch sauté pan over medium heat. Melt the butter in the pan but keep an eye on it; don’t let it burn.
Add cracked black pepper to the pan and toast for 2 minutes, stirring the whole time.
Next, add 1 cup of reserved pasta water and the fava beans, along with the pasta. Add the grated Pecorino and lemon zest.
While the pan is still on the heat, use tongs or a spoon to stir the pasta, coating it in the starchy pasta water and melting cheese to create a creamy sauce. If your pan looks a little dry, add a splash of pasta water. If your sauce looks too soupy, keep on cooking it down until it adheres to the pasta. Taste and season with salt if needed, but remember Pecorino is salty so you may not need much salt, if any.
Divide pasta among your bowls and shower with more grated Pecorino. Mangia!