Romanesco’s startling chartreuse turrets fade, when cooked, to a more respectable willow green. Too beautiful to deconstruct, this elegant head is best left whole for presentation. Quiet adornments keep the vegetable as star. If green peppercorns are not in your pantry, crushed pink ones (not true peppercorns, but so-called) add a sweet dimension; or fine-ground white pepper lends heat. Broccoflower can be substituted, but the dish will be less distinctive.