1/2 cup Capers in Salt
5 each 5 oz (1/4-inch-thick) slices Pancetta cut into 1/4-inch dice
1/2 cup golden raisins
3 Tbsp fresh lemon juice
28 oz (1 small head) cauliflower
2 Tbsp Extra-Virgin Olive Oil
3/4 stick (6 Tbsp) cold Unsalted Butter, cut into pieces
1/4 tsp Fine Sea Salt
2 pinches of sugar
2 Tbsp water
8 each Caperberries
Garnish Coarse Sea Salt; chopped fresh chives
Arrange racks to the upper and lower thirds of the oven, preheat oven to 350°F.
Rinse the Capers in Salt, transfer to a small bowl and soak in water for 30 minutes. Drain, rinse and set aside to dry.
Cook the Pancetta in a large skillet for about 10 minutes over moderate heat until crisp. Remove with a slotted spoon, drain on paper towels and pour off the fat. In a small bowl mix raisins and lemon juice.
Trim cauliflower stalks flush with base of crown, discarding stalk, then trim any leaves. Put cauliflower crown, stalk side down, on a cutting board. Cut a 1-inch slice from 2 opposite sides of crown and discard, then cut crown lengthwise into 4 "steaks," each about 3/4 to 1 inch wide.
Heat ½ the oil, ½ of the butter, ½ of the salt, and a pinch of sugar and pepper in a large skillet over moderate heat, swirling skillets occasionally, until butter begins to brown. Add cauliflower steaks to skillet and lightly season with salt and pepper, and then cook until undersides are golden, about 4 minutes.
Transfer skillet to oven and roast cauliflower, without turning, switching position of skillet halfway through roasting, until cauliflower is just tender and undersides are golden brown, 8 to 15 minutes (depending on thickness). While cauliflower is roasting,
Is roasting, bring water just to a boil in a 1-quart heavy saucepan, stir in Pancetta, Capers, raisins with lemon juice, and Caperberries. Add remaining 1/2 stick butter and stir until incorporated. Remove from heat and season with pepper.
Carefully invert cauliflower steaks with a spatula onto a platter and spoon sauce over them.