Peel the Potatoes and cut into 4-6 pieces. Put them in a pan and pour water until just covered then add sugar and stir. Boil them for 10 minutes until fork tender.
Drain the water but leave the potato in a pan. Put it back on the stove top with mid-low heat, shake the pan for 1 minute to remove excess water on the potatoes to prevent mushy texture.
While still hot, mash the potatoes with ricer or potato masher in a mixing bowl. Add salt, pepper and vinegar and stir. Let it stand for 10 minute until slightly cooled.
Add lime juice, Aji amarillo paste and Olive oil and mix until evenly combined. Cover and chill it in the refrigerator until ready to use.
In a mixing bowl, mix together shrimp, shallot, mayonnaise, salt and pepper.
Using ring mold, layer mashed potato, shrimp salad and sliced avocado as you like.You can topped with pico de gallo and serve with extra sauce.