How to Make It
Preheat the oven to 425° and position racks in the upper and lower thirds. Spread the hazelnuts in a pie plate. On a rimmed baking sheet, toss the cauliflower wedges with 1/4 cup of the olive oil and season with salt and pepper. Roast the hazelnuts on the upper rack for 10 minutes, until golden and fragrant. Let cool slightly, then rub them together in a kitchen towel to remove the skins. Coarsely chop the nuts. Roast the cauliflower on the lower rack of the oven for about 30 minutes, turning halfway through, until tender and nicely charred in spots.
Meanwhile, in a nonstick medium skillet, combine the garlic, toasted hazelnuts and the dates with the remaining 2 tablespoons of olive oil. Cook over moderately low heat, stirring, until the hazelnuts are golden brown, 2 to 3 minutes. Whisk in the lemon juice and 2 tablespoons of the dill and season with salt and pepper.
Arrange the cauliflower on a platter and spoon the warm hazelnut-and-date dressing on top. Garnish with the remaining 1 tablespoon of dill and serve warm or at room temperature.