Shrimp Boil until gain red. Then cooled. Removes heads and feelers. Shells of shrimp remain, put in a blender with a little water and blend to a homogeneous mixture. In the oil fry the chopped onion, then add the peeled and chopped tomato. Mix well, sprinkle with the chopped parsley, add salt and add pepper. Allow to simmer for 5-6 minutes over low heat. Then add the shrimp shells, already strained and cook another 5-6 minutes until a smooth sauce. Chilled shrimp pour the sauce and serve.