The onions may take up to an hour to fully caramelize, just make sure to continue stirring every 5-10 minutes so it doesn't burn. IF they happen to start burning the pan too quickly, add a small spoon of water into the pan deglaze.
Once onions are pretty much fully caramelized, begin cooking your pasta in a pot of salted water.
250 g fettuccine or choice of pasta
Add garlic into the pan with caramelized onions. Cook 2 minutes.
3 cloves minced garlic
Add heavy cream into the pan as well along with the cooked pasta and pasta water. Stir.
1 cup heavy cream, 1 cup salted pasta water
Grate in parmesan, add chili crisp, and chives.
2 tbsp chili crisp, ⅔ cup grated parmesan, 1 handful chopped chives