Step 1

Arrange a rack in the middle of the oven and heat to 425℉. Line a rimmed baking sheet with parchment paper; set aside. Coarsely grate a third of the cauliflower florets into rice-size pieces and set aside in a bowl.

Step 2

Break the remaining cauliflower into florets about 1 1/4 inches wide, and place in a large bowl. Add the onion and any cauliflower leaves. Drizzle with 2 tablespoons of the oil, sprinkle with 1/4 teaspoon of the salt, and toss to combine. Transfer to the baking sheet and spread into an even layer.

Step 3

Roast until cooked through and golden brown, about 20 minutes. Remove from the oven and set aside to cool.

Step 4

Transfer the roasted vegetables to a large bowl. Add the reserved grated cauliflower, parsley, mint, tarragon, pomegranate seeds, pistachios, lemon juice, cumin, remaining 3 tablespoons oil, and remaining 1/4 teaspoon salt. Toss gently just to combine. Transfer to a platter and serve.