Place potatoes in large pot with enough water to cover completely. Boil over medium-high heat for about 15 minutes or until potatoes are tender when pierced with a fork. Drain water. Let potatoes cool, then peel. Slice and set aside.
Place bread in a medium bowl. Add evaporated milk; set aside to soak.
Place chicken in a medium saucepan with enough water to cover completely. Boil over medium heat for 20 minutes or until chicken is cooked through. Remove from heat; place chicken in a separate container to cool. Strain broth, reserving 2 ½ cups. Shred chicken.
Heat oil in a large skillet over medium heat. Add onion and garlic; cook, stirring frequently, for about 3 minutes or until tender. Stir in aji paste; cook for 5 minutes. Remove from heat.
Place soaked bread with evaporated milk, nuts, cheese, bouillon and aji mixture in food processor or blender; cover. Process for 20 seconds. Add some reserved chicken broth if necessary.
Return mixture to skillet; add reserved chicken broth. Cook over medium-low heat until gently boiling. Stir in shredded chicken; cook for 5 minutes.
Serve with potatoes, eggs, olives and a sprig of parsley.