Over an open flame or in a small, very hot skillet, blister the tortillas. While the tortillas are heating, fry your eggs in another non-stick skillet. Heat the sausages and cut into pieces. Divide the eggs, sausage (if using), avocado slices and place onto the tortillas. Sprinkle on the cheese and let it melt. Add the slices of red onion, fresh chopped cilantro, sriracha, a squeeze of lime juice, a pinch of sea salt and a grind of black pepper. Serves 4.