Put 1/2 can evaporated milk, 1/2 onion, diced (I like to sauté it with some olive oil), 6 water crackers, salt, pepper, 1 tablespoon of yellow chili pepper (sold canned in supermarkets) and 1/2 cup of mayonnaise in a blender and blend until soft.
Toast the bread and spread huancaina-style mayonnaise on it, then add lettuce or arugula leaves, and rolled smoked salmon slices.
Decorate with rough bindweed fruit, black sesame seeds, huaicaina-style mayonnaise and sour cream. And voilà!