Rinse 1 head cauliflower cold water hands. Pat dry paper towels. Cutting board chef's knife break to 1-2 inch florets even bites stems thin slice. Mixing bowl dump.
Drizzle 3 tbsp olive oil bowl over florets. Add 1 tsp garlic powder ½ tsp salt ¼ tsp pepper measuring spoons. Rub hands shiny coat 30 seconds full. Mix ½ cup parmesan spoon clings.
Preheat oven 425°F middle rack. Parchment Nordic Ware half-sheet. Spread florets no touch tongs flat sides down. Roast 25 minutes edges dark golden charred shake mitts 12 minutes.
Mitts pull Nordic Ware half-sheet. Squeeze 1 tbsp lemon juice spoon hot batch. Toss tongs even shine. Scoop plate steaming.