Place the potatoes in a large pot and cover with water. Bring to a boil over medium-high heat. Cook for 30 minutes or until a paring knife slides into the potatoes without any resistance. Drain the potatoes and let them cool slightly. Slice the potatoes into 1/2-inch rounds and set aside.
Combine the cheese, evaporated milk, oil, chile, garlic, and the lime juice in a blender and puree until smooth. The sauce should be creamy and pourable. If the sauce is too thick, add water, 1 tablespoon at a time, until the sauce is thinned out.
Arrange the lettuce leaves on a platter and top with the sliced potatoes. Pour the sauce over the potatoes. Garnish with slices of hard boiled egg and olives. Garnish with chopped parsley. Serve chilled or at room temperature.
A great substitute in this recipe, for feta cheese is cream cheese.