How to Make It
Cook pasta in a large pot of boiling, salted water until almost al dente, 8 to 10 minutes. Drain pasta, reserving ½ cup of the pasta water.
Meanwhile, heat oil in a large skillet over medium-high. Add sausage and mushrooms and cook, stirring often, until they begin to brown, about 5 minutes. Add corn, leeks, and salt and cook, stirring often, until corn is tender and leeks are soft, about 4 minutes.
Add butter, lemon zest, and reserved pasta water and cook, tossing, until liquid reduces and coats pasta, about 3 minutes. Add lemon juice and toss to coat. Serve topped with basil.