First prepare lime crema by combining sour cream with lime juice from about 1/4 to 1/2 limes and cilantro (1-2 tbsp). Combine and set aside. This will be your dressing.
In medium bowl, combine tomatoes, green onions, about remaining cilantro and 1/4 to 1/2 lime. Set aside to add to tacos.
Preheat your oven broiler to high.
Cut the fish fillets into about 10 pieces and place in a bowl.
Season the fish with the oil, salt, pepper, cumin, chili powder and paprika and turn to coat evenly.
Place the fish on a greased baking sheet covered with aluminum foil.
Place under the broiler and cook 4-5 minutes each side, remove from oven once fully cooked and nicely browned. Immediately drizzle squeeze of lime juice over tacos - 1/4 of a lime should do it.
Warm tortillas in microwave for a few seconds or in oven for 1-2 minutes.
Top with fish with the tomato, onion and cilantro salsa lime crema.