If not using pre-riced cauliflower, chop the cauliflower into large florets and then put through the feed tube of a food processor fitted with the grating attachment. Alternatively, the cauliflower can be grated with a box grater. Measure 5 cups; save the rest for another use. (If you end up with a mere cup or so leftover, it will fit in the pan size mentioned below. Just add an extra teaspoon or two of oil. You may increase the garlic by 1 clove, if desired, and very slightly round the 1/2 cup of Parmesan.)
Heat the oil and butter in a large skillet (12-inch diameter works well) over medium heat. Add the garlic, and sauté just until aromatic, about 30-60 seconds. You don’t want it to burn. Immediately add the cauliflower, stir to coat with the oil mixture, and increase the heat to medium-high. Season the cauliflower lightly with salt and pepper, and sauté until tender, about 6-8 minutes. (Tip: I like the cauliflower to be browned in spots, so I press it into an even layer, let it sear for a minute or two or until golden brown in spots, and then stir and repeat until tender but not mushy.)
Remove the pan from the heat, stir in the Parmesan cheese. Taste and add another pinch of salt and pepper if needed. Garnish with fresh parsley, chives, or paprika, if desired. Leftovers can be gently reheated in the microwave or oven.
