Steps
1. Slice the onion thinly.
2. Heat the olive oil in a pan over medium heat.
3. Add the sliced onion to the pan and cook, stirring occasionally, until the onion is caramelized and golden brown, about 20 minutes.
4. While the onion is cooking, cook the pasta according to the package instructions until al dente.
5. Drain the pasta and add it to the pan with the caramelized onions.
6. Toss the pasta with the onions, season with salt and pepper to taste.
7. Serve the pasta hot, garnished with grated Parmesan cheese.