Preheat oven to 425 degrees.

Coat cauliflower in olive oil and sprinkle generously with salt and pepper. Spread on a rimmed baking sheet and place in preheated oven. Roast 10 to 15 minutes, turning once during cooking, until just beginning to brown but still somewhat firm in texture. Set aside to cool.

DRESSING: Mix all ingredients in a jar or salad shaker and shake to emulsify.

ASSEMBLE SALAD: on a serving platter, arrange mixed greens. Top with cooled cauliflower, chickpeas, raisins, cheese, and pistachios. Pour dressing over salad and serve immediately.