In a small pan with oil add
chile de Arbol. Cook until slightly dark. Remove from pan and place in a bowl all the chiles and oil. Let cool for a couple of minutes then pour into a
blender. Blend for 30 seconds then pour out most of it out into a bowl and reserve. Leave some pepper and oil in the
blender.
Add garlic, salt, lime juice, peppercorns and mayonnaise to the
blender and blend for 30 seconds then pour into a bowl with the shrimp which is completely defrosted and rinsed thoroughly. Let marinate while you
slice and dice the onions