1. Preheat the oven to 425°. In a small saucepan set over medium heat, melt the butter. Continue to cook, swirling often, until the butter is deep brown, and fragrant, about 5 minutes. Turn off the heat and strain the brown butter through a fine-mesh strainer into a small bowl.

2. On a baking sheet, toss the cauliflower with the brown butter, honey, salt and pepper and place in the oven. Roast until golden brown and tender, about 20 minutes. When the cauliflower is cool, place in a large bowl and set aside.

3. Meanwhile, in a medium saucepan set over medium-low heat, combine the onion, jalapeño, red pepper, apple cider vinegar, sugar, mustard seeds, celery seeds and turmeric. Season with salt and bring to a simmer. Cook, stirring frequently, until the vegetables are tender and the mixture is dry, about 15 minutes. Transfer to a small bowl and set aside to cool.

4. Make the vinaigrette: In a medium bowl, whisk together the shallot, Champagne vinegar, lemon zest and juice, thyme, mustard, salt and pepper. Slowly whisk in the olive oil until the dressing is thick and creamy. Pour the vinaigrette over the cauliflower, add the arugula and reserved pepper relish and toss to combine.

5. To serve, divide the salad among four plates and top with the crumbled chèvre.