Preheat oven to 200°C, or preheat grill to hot. Heat half of oil in a large frying pan on high. Add mince and cook for 5 minutes, stirring to break up any lumps, until no longer pink.
Place tacos in oven or under grill for 2-3 minutes, until crisp.
Meanwhile, combine mince, diced avocado, tomato and onion in a bowl. Stir through garlic, juice, remaining oil, Tabasco, ground coriander and cumin. Season to taste. Place ½ cup of mince filling in each taco shell. Top each taco with a spoonful of mashed avocado and coriander leaves and serve.