Heat the cooking oil in a frying pan.
Lightly fry the tortilla on both sides. Drain on a rack while you prepare the rest of the components of your huevos rancheros.
Into the remaining oil, crack the egg on one side of the frying pan. Sprinkle with salt and pepper. On the opposite side of the pan, scatter the chorizo slices. Cook until the egg is set and the chorizo slices are heated through.
Assemble the dish. Lay lettuce leaves on a plate. Arrange the tortilla on top. Lay the egg on top of the tortilla. Spoon the chorizo slices, guacamole, jalapeño, corn and tomatoes around the egg.
Drizzle lime or lemon juice over the chopped tomato and corn.
Sprinkle in some torn cilantro or parsley. Serve.