Heat the grill to high and line a large baking tray with foil. Mix the smoked paprika and cumin in a small bowl. Rub the spices over the salmon fillets and put them on the baking tray. Pop under the grill for 8-10 mins until cooked through.
While the salmon cooks, combine the yogurt with the garlic and season to taste. In another bowl, combine the avocados, onion and tomatoes. Add the lime juice, season and scatter with coriander.
Warm the taco shells in the oven, following pack instructions. Flake the salmon and serve with the tacos, avocado salsa, yogurt and lime wedges.