- 1 head cauliflower, sliced into 1-inch slices, or cut into 1-to-2-inch florets
- Olive oil
- Salt and pepper, to taste
- 3 tablespoons Champagne vinegar
- 1 tablespoon Dijon mustard
- 2 teaspoons honey, or to taste
- 6 tablespoons walnut oil
- 1/4 cup toasted chopped walnuts
- 2 tablespoons chopped fresh parsley
Preheat oven to 425° F. Place a rimmed sheet pan in the oven to preheat for 3 minutes. Meanwhile, place cauliflower in a large bowl and toss with olive oil to coat; season with salt and pepper.
Place cauliflower on the hot sheet pan (this will give it a nice “sear” or caramelization) and roast until fork tender and caramelized, 10 to 15 minutes. Remove cauliflower from the oven and keep warm, while preparing vinaigrette.
In a small bowl, combine vinegar, mustard and honey until well combined. Very slowly begin to whisk in walnut oil, drop by drop, until vinaigrette begins to emulsify. As vinaigrette becomes thicker, add remaining oil more quickly. Stir in walnuts and parsley; season with salt and pepper.
Gently toss cauliflower with vinaigrette and transfer to a serving platter. Serve warm or at room temperature.