- 1 small head of cauliflower (about 1 3/4 pounds)
- 1 teaspoon coarse kosher salt
- 6 tablespoons (3/4 stick) butter
- 2 tablespoons fresh lemon juice
- 2 tablespoons whole grain Dijon mustard
- 1 1/2 teaspoons finely grated lemon peel
- 1 tablespoon chopped fresh parsley
- Preheat oven to 400°F. Butter rimmed baking sheet. Cut cauliflower in half, then cut crosswise into 1/4-inch-thick slices. Arrange slices in single layer on prepared baking sheet; sprinkle with salt. Roast until cauliflower is slightly softened, about 15 minutes.
- Meanwhile, melt butter in small saucepan over medium heat. Whisk in lemon juice, mustard, and lemon peel.
- Spoon mustard-lemon butter evenly over cauliflower and roast until crisp-tender, about 10 minutes longer. DO AHEAD Can be made 2 hours ahead. Let stand at room temperature. If desired, rewarm in 350°F oven until heated through, about 10 minutes.
- Transfer cauliflower to platter. Sprinkle with parsley and serve warm or at room temperature.