In a skillet, sautée ⅓ cup chopped onion in 2 tablespoons olive oil over medium heat until lightly golden.
Add 6 tablespoons yellow pepper paste and cook, stirring, for 1 minute.
Use an immersion blender directly in the pan or transfer the mixture to a blender.
Add 9 ounces queso fresco, ½ cup evaporated milk, 3 or 4 water crackers or saltines, salt and pepper to taste, and ¼ cup olive oil. Blend until smooth.
Add ½ teaspoon lime juice and check seasonings, adjusting if necessary. If you want a thinner consistency, add a few more tablespoons olive oil.
Meanwhile, cook 2 pounds baby potatoes in a large pan of salted water. Drain, transfer to a large bowl, add a couple of tablespoons olive oil, toss and let cool.
In a serving bowl put potatoes and toss with some of the pepper sauce.
Add some more sauce, sprinkle with 2 tablespoons chopped fresh parsley and arrange 4 hard-boiled eggs, cut into quarters, around the edges of the bowl. Scatter ½ cup black olives on top.
Serve with a bowl of extra sauce drizzled with olive oil.