1. To prepare the filling, warm the oil in a small pan over medium heat; once hot add the chorizo, chilli and spring onions.
2. Immerse the tomatoes in boiling water for a few minutes to loosen the skin, then peel, discard the core and roughly chop.
3. Add the chopped tomato to the filling mixture, season to taste and cook, covered, over low heat for 10–20 minutes until disintegrated (the longer the better).
4. While cooking the filling, prepare the omelette. Lightly coat a 15-cm nonstick pan with the oil and leave to warm over a medium/high heat.
5. In a bowl, gently whisk the eggs with the milk, salt and black pepper.
6. Pour the egg mixture into the preheated pan and swirl the mixture around so that a thin layer sticks to the sides. Leave to cook for about 5 seconds without moving the pan, then, as the omelette is almost set, swirl any remaining liquid mixture around the pan to thicken the crispy edges.
7. Once these edges start to pull away from the pan, place two-thirds of the chorizo filling on one side of the omelette (leaving a margin around the edges).
8. Cook until the edges have completely pulled away from the pan.
9. Run a spatula all the way around the pan to ensure the omelette is not stuck and then gently fold the one side over the filling.
10. Leave to sit in the pan for about 30 seconds after removing from the heat before using a spatula to slide the omelette onto a plate.
11. Top the omelette with the remaining third of the chorizo mixture, three slices of avocado, three slices of tomato and a sprinkle of fresh cilantro.
Serve immediately with warm tortillas, arroz rojo or toast.
This recipe is courtesy of A Bite of Latin America: A Culinary Diary by Suzie Chatz-Anderson, published by Human & Rousseau. Available at good book shops for approximately R340.