Brown the butter. Put the butter in a small frying pan over medium heat. Once it melts, it’ll start bubbling. Then the bubbles will subside. And then my friends…and then it will start developing lovely toasty flavors and aromas. Watch it closely once it starts smelling nutty. You want it brown, not burned. See how brown you can get it before it develops burned flavors. It’s a fun game. Once it’s nice and nutty, throw in the sage leaves and remove from the heat. The sage leaves will crackle a bit. That’s perfectly normal and it’s just the sound of them crisping up nicely.
Cook the pasta. Cook it according to the package directions. I usually do a minute less than the package calls for because I like it al dente. I usually end up cooking it for a minute in the sauce, which finishes it perfectly. Oh, and I shouldn’t have to explain this again, but salt the hell out of your water. It should taste like the ocean before you add the pasta. If you’re worried about sodium levels, fear not. Most of the salt stays in the water. But you do want to flavor the pasta, since it’s flavorless otherwise.
Mix and Serve! Once the pasta is finished, remove it with tongs or a skimmer and dump it straight into the pan with the butter and sage. Add the cheese, a squeeze of the lemon, and some pasta water (1/4 to 1/2 cup) and toss to combine.