Break into even florets, roughly 1–1½ inches across — too big and centers stay raw, too small and they go mushy. To steam whole, cut out the core: flip upside down and carve a deep cone around the central stem with a paring knife, then remove and discard. Rinse under cold water and shake off excess moisture before placing in the steamer basket.

Fill a pot with 1–2 inches of water, bring to a boil over medium to medium-high heat. Arrange florets in a single layer in the steamer basket; place a whole head core-side down. Set the basket over the boiling water, cover tightly, and reduce heat slightly to keep a steady steam. Florets: check at 6 minutes; total time 6–10 minutes depending on size and desired tenderness. Whole head: 10–15 minutes or more. Avoid lifting the lid repeatedly. Doneness: pierce the thickest part with a fork or paring knife. Crisp-tender = slight resistance. Soft for mashing = fork slides in with almost no resistance. If more time is needed, replace the lid and check every 2–3 minutes.

When the florets hit your desired tenderness, pull the basket off the heat immediately and transfer to a plate — they keep cooking if you leave them. Serve warm or at room temperature. Finishing options: olive oil, salt, and pepper; garlic and caper sauce; melted butter with cheese (bake briefly to melt); or blend into a purée or stir into a cheese sauce. Biggest mistake: overcooking. Florets left too long go waterlogged and fall apart. Watch closely once you hit the low end of the time range. Second mistake: adding cauliflower before the water is at a full boil — leads to uneven cooking and longer times. Always start with actively boiling water and a tight-fitting lid.