1. Peel, butterfly and devein the shrimps. Place in a bowl and keep aside.
2. In a Mexican stone mortar and pestle (Molcajete), crush the garlic and the green chili pepper to a coarse paste, pulverize it completely.
3. Juice the limes into a measuring cup.
4. Peel, pit and slice the avocado into wedges.
5. Halve, deseed and slice the tomatoes into wedges.
6. Combine the lime juice and the crushed garlic and chili. Give a good mix.
7. Pour this mixture over the shrimp.
8. Stir and squish the shrimp so that they are soaked in the lime juice. Keep stirring occasionally after every 3-4 minutes.
9. You can chop the shrimp if you like once they have been marinated for 10 to 15 minutes.
10. Serve the Raw shrimp salad topped with avocado and tomato wedges. Enjoy over tostadas or soft tortillas