Bring a pot of water to a boil over high heat. While you wait for the water to boil, heat the olive oil over medium heat in a 10-inch skillet. Season both sides of the chicken with salt. Cook the chicken for four to five minutes on one side. Turn it and cook it another few minutes or until it’s cooked through. Transfer the chicken to a clean plate. Once the water is boiling add the pasta and cook it according to package directions.

While the pasta boils, melt the butter in the same skillet over medium heat. Add the leeks and saute them in the butter, stirring occasionally, until they’re softened. Add the lemon juice and as it simmers scrape up the browned bits off the bottom of the pan. Slice the chicken into bite-sized pieces and transfer it to the pan with the butter and leeks.

Set aside a couple of tablespoons of the starchy pasta water. Transfer the cooked pasta along with the reserved pasta water to the skillet and toss to coat the pasta in the butter. Add the cheese and toss the pasta with it until the cheese has melted. Transfer the pasta to two bowls. Top each serving with black pepper and chopped parsley, if using.