Preheat the oven to 400°F. Spread the chickpeas out on a parchment lined baking sheet. Sprinkle them with a bit of lime zest, chili powder, salt, pepper, and 1 tablespoon of the olive oil. Toss the chickpeas to coat and slide the tray into the oven. Roast until lightly crispy and golden, about 20 minutes.
Whisk together the remaining lime zest, lime juice, olive oil, salt, pepper, grainy mustard, and maple syrup. You can also shake this up in a sealed container. Add a splash of water if it seems quite thick. Set aside.
Start turning the cauliflower into rice in batches. Place a few handfuls of the florets into the bowl of a food processor fitted with the "S" blade. Pulse the florets until you have small, rice-like bits of cauliflower. Scrape the riced cauliflower into a large bowl. Repeat with remaining cauliflower.
Pour the dressing over the cauliflower rice, season with salt and pepper, and toss to coat.