Chop the cauliflower into bite-sized florets, starting by removing the stem, then breaking the head into larger pieces. Add florets to a bowl, drizzle with oil and season with salt and pepper. Place cauliflower on a baking sheet and roast for 20 - 30 minutes until starting to brown, stirring every 10 minutes.
While cauliflower is cooking, whisk together all the dressing ingredients until smooth. Taste and adjust salt and pepper accordingly. Set aside.
When cauliflower is done roasting, let rest on the pan until cool enough to touch. Transfer back to the mixing bowl and add remaining salad ingredients.
Pour dressing over salad and mix until fully combined. Season with a touch more salt and pepper if desired.
Serve immediately, or chill in fridge for 30 minutes and serve cold.