Bring a large pot of salted water to a boil. Add the pasta and cook, stirring occasionally, until it reaches an al dente texture according to the package directions. Before draining, reserve at least ½ cup of the starchy pasta water.

While the pasta cooks, place a large saucepan over medium-low heat. Pour in the evaporated milk and bring it to a gentle simmer.

Add both packages of Boursin cheese to the simmering milk. Stir continuously until the cheese is completely melted and the mixture is well combined, which should take about 3 minutes.

Continue to simmer the sauce, stirring occasionally, for another 2 to 3 minutes until it becomes slightly thickened and glossy. Season the sauce with ½ teaspoon of kosher salt.

Add the cooked pasta directly into the sauce along with a splash of the reserved pasta water. Stir gently over medium-low heat until the sauce thoroughly coats the pasta. If the sauce is too thick, add more pasta water a tablespoon at a time. Taste and add more salt if needed before serving.