Peel, wash and halve the potatoes and cook in boiling salted water for about 20 minutes. Wash and clean the tomatoes and cut them into fine cubes. Wash the lime hot, grate dry, peel thinly with a peeler and cut into strips.
Wash the chives, shake dry and cut into small rolls. Halve the lime, squeeze the juice. Halve avocado, remove core and remove flesh from skin with a tablespoon. Heat milk.
Drain the potatoes. Add milk, avocado and 4 tablespoons lime juice. Mash them with a potato masher to make puree. Fold in diced tomatoes and chive rolls. Season to taste with salt and coriander.
Peel and slice the garlic. Peel the prawns, except for the tail fin, and remove the intestines. Wash the shrimps and dab them dry. Heat the oil and fry the prawns for about 4 minutes while turning.
Add the garlic after 2 minutes. Season with salt and pepper. Serve and garnish with lime zest.