Pat the cauliflower florets completely dry with paper towels before tossing with oil to ensure proper caramelization and prevent steaming during roasting.

Cut all cauliflower pieces to approximately the same size so they roast evenly and finish cooking at the same time for consistent caramelization.

Arrange cauliflower in a single layer with some space between pieces; overcrowding causes steaming rather than the desired golden-brown crust.

Use a microplane or box grater to freshly grate Parmigiano-Reggiano just before plating, as pre-grated cheese can become clumpy and won't melt beautifully over the warm vegetables.

Add whole shallots and unpeeled garlic cloves at the start, then add minced garlic halfway through to prevent burning while still building deep, sweet caramelized flavors.