Instructions
Begin by gathering all necessary ingredients for the recipe.
In a large pot, pour in lightly salted water and bring it to a vigorous boil. Once boiling, add the pasta and allow it to return to a boil. Cook the pasta uncovered, stirring occasionally, until it reaches a tender yet firm texture, approximately 8 to 10 minutes. After cooking, drain the pasta and transfer it to a large mixing bowl.
While the pasta is cooking, heat olive oil in a frying pan over medium-low heat. Add the chopped onion and sauté until it becomes tender, about 3 minutes.
Incorporate the pesto along with salt and pepper into the pan, stirring until the mixture is warmed through.
Finally, combine the pesto mixture with the hot pasta. Toss in the grated Parmesan cheese and mix well to ensure that the pasta is thoroughly coated.