Season the shrimps with salt and pepper. Place a skillet over medium high heat and pour the olive oil onto it. Once the oil is heated, add the shrimp and cook one layer for 2-3 minutes then turn to the other layer. Remove the shrimps from the pan and transfer them to a cutting board. Chop into pieces and place in a large mixing bowl.
Squeeze one lime over the shrimps to marinate. Stir well then set aside.
Add the diced avocado, tomato, and cucumber to the shrimps.
Mix the diced onion and chopped cilantro into the bowl. Stir together until all the ingredients are well-combined.