1. Heat the olive oil in a large heavy-based frying pan and when hot, drop in the butter. When you hear the butter sizzle, place in fish skin side down and fry until golden and crisp, then turn and cook the other. Remove fish from pan (remember it keeps cooking a little after being removed from the heat) and keep warm while you quickly fry the eggs.
2. Turn the heat to high and using the leftover fat from cooking the fish, carefully break eggs into the pan and let them cook for 30 seconds then reduce heat to medium. To achieve a pinkish yolk, begin basting the eggs with the hot fat so the tops of the eggs are lightly cooked, too. After 1 minute the eggs should be crispy around the edges and cooked.
3. To serve, place a warmed tortilla on each plate, top with a fried egg. Place fish around the tortilla and scatter around the diced tomato and avocado. Scatter over a few fresh chilli slices and top with soft herbs or babygreens. Season with salt and freshly ground black pepper and place a lemon or lime wedge on each plate for squeezing over the fish.

Kathy recommends

• Pan-fry fish fillets whole. Or you can cut to give thick strips of fish — this is more of a presentation element.