1. In a large mixing bowl, combine the lemon juice, 1½ teaspoons of dried chili or the pequin chilies, ½ teaspoon of salt and a few grindings of black pepper.
2. Add the onion rings, turning them about with a spoon to coat them evenly with the mixture. Cover the bowl and set aside to marinate at room temperature while you boil the potatoes.
3. Drop the potatoes into a large pot of lightly salted boiling water (enough to cover them completely), and boil the potatoes briskly until they are tender but not falling apart.
4. Meanwhile make the sauce by combining the cheese, cream, turmeric, chopped fresh chili, ½ teaspoon salt, and a few grindings of pepper in the jar of a blender. Blend at high speed for 30 seconds, or until smooth and creamy. (To make the sauce by hand, beat the ingredients together until they are well combined.)
5. In a heavy 10-inch skillet, heat the olive oil over moderate heat. Pour in the cheese and cream sauce, reduce the heat to low, and cook, stirring constantly, for 5 to 8 minutes, or until the sauce thickens.
6. To assemble, arrange the potatoes on a heated platter and pour the sauce over them. Drain the onion rings and strew the rings and fresh chili strips over the potatoes. Garnish with eggs, black olives and lettuce.
