Shrimp Ceviche

https://www.seriouseats.com/shrimp-aguachile-ceviche-lime-cucumber-recipe 

• Sashimi grade, head on shrimp (1 lb)

• Serrano chilis (2)

• Limes (4)

• Red onion (1)

• Cucumber (1)

• Tostados

• Avocado