Preheat the oven to 400 degrees F. Line a baking sheet with foil or parchment.
Break up the cauliflower into evenly sized florets about 1-inch long. You can use a knife to divide the large florets if they don't break easily.
In a large bowl, whisk together 1/3 cup oil, coriander, mango powder, if using, cumin, salt and pepper, to taste. Add the florets and, using your hands, gently toss to coat.
Pour the prepared baking sheet and roast until tender and slightly browned, 30 to 40 minutes, tossing halfway through.
Meanwhile, in a small bowl, combine the yogurt with the lime zest, a splash of extra-virgin olive oil, salt, pepper, and a squeeze of lime (as much as you like).
Serve the cauliflower with a dollop of yogurt on the side, and enjoy a whole new way to eat cauliflower!