How to Make It
Preheat broiler to high. Combine cauliflower, 1 1/2 tablespoons oil, and thyme in a large bowl. Spread cauliflower mixture in a single layer on a foil-lined baking sheet. Broil 8 to 10 minutes or until browned and tender, stirring once after 4 minutes.
Combine remaining 1 1/2 tablespoons oil, rind, juice, capers, mustard, pepper, and salt in a large bowl, stirring with a whisk. Add roasted cauliflower; toss to coat.