Squeeze the lime juice in a large bowl and place all the shrimp in this juice. You must have enough juice to drown the shrimp in. Set aside 4 limes.

Squeeze 4 lemons into the blender. Cut the tips from the serrano chiles and toss the chiles into the blender and puree the mixture. Add this mixture into the shrimp.

Slice the red onion and the cucumbers and set aside in a bowl. After the shrimp has been sitting in the lime juice for about 20 mins add the sliced onions and cucumbers into the large bowl as well. Let all ingredients sit and cook for about 45 mins.

Sprinkle salt and pepper

Serve cold use tostadas or tortilla chips and enjoy!