Bring the cream to a simmer over medium heat; after it has simmered all the way to the edges, remove from heat and put aside.
While still holding the rings together, gently transfer the onions from the oven to a baking dish.
After gently tossing the onions with the cream mixture, top with the grated parmesan.
Wrap the foil securely around the baking dish and put it back in the oven.
After 20 more minutes in the oven, gently remove the foil and continue roasting for 5 more minutes.
When the onions start to become a little brown and caramelized, take them out of the oven.
Savor it!
