Preheat your oven to 425F. Spray a 9" square baking pan with oil.
Sprinkle shredded Parmesan cheese over the bottom of the baking pan.
Arrange Brussels Sprouts halves, cut side down, over the top of the Parmesan cheese.
Bake for 30 minutes or until the Parmesan cheese and Brussels sprouts turn brown.
Remove from the oven and let cool for 10 minutes. This will allow the cheese to harden.
Serve warm.
Video
Notes
If you use frozen Brussels Sprouts they will release water while they cook and be soggy at the end of the baking time. Don't do this, it's not enjoyable.
You can use pre-grated Parmesan cheese, but we prefer using fresh.
Do not overcrowd the baking dish. You want the cut half of each Brussel sprout to be in full contact of the Parmesan cheese.
Make sure you roast uncovered, otherwise they will steam and be soft.
Don't forget to trim off the fibrous base. Very hard to chew.