Steps
1. Slice the onion thinly.
2. Heat the olive oil in a large skillet over medium heat.
3. Add the sliced onion to the skillet and cook, stirring occasionally, until the onions are caramelized and golden brown, about 20 minutes.
4. While the onions are cooking, bring a pot of salted water to a boil and cook the pasta according to package instructions.
5. Drain the cooked pasta and transfer it to the skillet with the caramelized onions.
6. Toss the pasta with the onions, salt, and black pepper until well combined.
7. Serve the pasta in bowls and sprinkle with grated Parmesan cheese.