Caramelized Onion-and-Mushroom Pasta

Caramelized onions take a while to reach their beautiful golden-brown color, but the wait is worth it! This recipe requires patience but is otherwise very simple. I was playing around with the onion-and-mushroom mixture when I realized it would be delicious as a tart filling or doubled as a pasta topper. Hot cooked pasta is simply dressed in mascarpone cheese, which melts and coats the noodles with a creamy, luscious sauce that enhances the umami essence o