1. Preheat oven to 350.
2. Lightly coat baking dish with non-stick spray.
3. In large skillet, cook onions and garlic in butter over medium heat until onions are soft.
4. Stir in brussels sprouts and thyme.
5. Cook for 5 minutes or until onions begin to brown.
6. Add broth and bring to a boil.
7. Cook 7-8 minutes, stirring occasionally until broth is nearly evaporated.
8. Add cream and nutmeg.
9. Cook for 4 minutes or until broth begins to thicken.
10. Transfer to baking dish, stir in 1/2 cheese, salt and pepper.
11. Sprinkle with remaining cheese.
12. Bake, uncovered, 20-25 minutes.