Thaw the fish quickly by putting the fillets in a bowl of lukewarm water (after removing plastic, of course). Make the marinade and evenly coat the fish in it in a ziploc bag or shallow dish. It's best to marinate it 1-24 hours in the fridge. Preheat the oven to 425. Peel and dice the sweet potatoes into 1.5" bite sized pieces. Put the sweet potatoes on a rimmed cookie sheet. Drizzle olive oil all over and season well with salt and pepper. Use your hands to coat evenly. Trim the broccoli florets and put them on a rimmed cookie sheet. We like a good blend of larger ones and smaller ones. Drizzle with olive oil, season with salt and pepper, coriander, cumin, and (to a much lesser degree) chili powder. Use your hands to coat evenly. I like to arrange the big pieces on the perimeter of the cookie sheet so they cook quicker. The sweet potatoes will take 30-45 minutes to cook thoroughly until soft (depending on their size and the amount you make). The broccoli will take 20-30 minutes to cook until tender depending on the size of stalks. Stir both the potatoes and broccoli gently 1-2 times while roasting. Dredge the marinated fish fillets in the flour mixture and cook in a skillet/on a griddle until flaky.