Step 1

Preheat oven to 450°F. On a baking sheet, drizzle cauliflower with 2 Tbsp. oil; sprinkle with 1/2 tsp. salt and toss to coat. Spread in a single layer. Roast, stirring once or twice, until golden brown and tender but not mushy, about 15 minutes. Taste a floret for doneness; larger florets may take slightly longer to cook.

Step 2

Make salsa verde: In a small bowl, stir parsley, chives, capers, mustard, lemon zest, pepper and remaining 1/4 tsp. salt until well mixed. Stir in remaining 4 Tbsp. oil and olives. (The salsa verde can be made up to 1 day in advance. Refrigerate, covered, until serving.)