For the cauliflower:
1 large (at least 3 pounds) or 2 small heads cauliflower
4 tablespoons olive oil
Salt and pepper, to taste
1 1/4 teaspoons ground turmeric
1 teaspoon coriander seeds, coarsely crushed with a rolling pin or mortar
1 lemon, sliced into wedges
For the butter:
4 tablespoons unsalted butter, at room temperature
1 tablespoon chopped fresh ginger
1 teaspoon curry powder
1 teaspoon finely grated lemon zest
1/8 teaspoon salt
Pinch of black pepper
For the fish:
4 (6-ounce) Alaska rockfish fillets
2 tablespoons olive oil
1/2 teaspoon salt
1/8 teaspoon freshly ground black pepper
2 scallions, finely sliced, including some of the green part (for garnish)
2 tablespoons chopped parsley
Preheat the oven to 450ºF. Spray or brush a rimmed baking sheet with olive oil.
Remove all the outer leaves from the cauliflower and stand it upright on your cutting board (trim the bottom of the stem as needed to keep the cauliflower stable).
With a large knife, cut it into 3/4-inch thick slices. You will have some “scraps”—slices or florets of cauliflower that are not attached to the core and fall apart, but you should get at least 4 slices that are intact.
Brush both side of the steaks with oil, and toss the “scraps” with a little oil as well. Arrange them on the baking sheet, and sprinkle generously with salt and pepper, followed by the turmeric and coriander. Squeeze the lemon wedges over top.
Roast for 25 to 30 minutes, or until golden and tender when you insert the tip of a knife into the steak. Remove from the oven and set aside.
Lower the oven temperature down to 400ºF.
Remove about 1 teaspoon of zest from the lemon and squeeze about 1 1/2 tablespoons of juice. In a food processor, process the butter, lemon zest and juice, ginger, curry powder, 1/8 teaspoon salt and a pinch of black pepper until combined. Scrape down the bowl once or twice as needed. Transfer to a bowl.
Line a baking sheet with foil and lightly brush with oil or spray with olive oil spray. Set the fillets on the baking sheet. Brush with 2 tablespoons of olive oil and sprinkle generously with salt and pepper.
Bake in the oven at 400ºF for 6 to 8 minutes, or until the fish is cooked through and opaque.
Remove from the oven, cover loosely with foil, and let the fish rest for 5 minutes.
The cauliflower can be served warm or room temperature; return it to the oven for a few minutes to rewarm, if desired. Transfer the cauliflower to a large platter. Set the fillets on top and dot each fillet with the curry butter. Sprinkle with chopped scallions and parsley and serve.