
Peel and deveined the shrimp. Reserve the shells.
Make the broth: In a medium pot, add the water, onion, garlic, bay leaf and salt. On medium high heat, bring to a soft boil. Add the shrimp shells, cover with a lid and cook for about 20 minutes.
Remove the shrimp shells from the broth and discard.
Add the shrimp to the hot liquid, stirring occasionally, until just cooked through and no longer translucent on the inside, 2 to 3 minutes (careful not to overcook! Shrimp turns rubbery when overdone).
Transfer the shrimp into a bowl with ice and water to let it cool. Remove the broth from heat and allow it to cool. Reserve for later.
In a medium bowl mix the clamato juice, ketchup, lime juice, Maggi seasoning, hot sauce and shrimp broth.
In a large bowl, add the cooked shrimp, cucumber, onion, tomato, jalapeño (or serrano), cilantro, salt & pepper. Add the broth & clamato mixture and mix to integrate. Add the chopped avocado and mix gently to integrate.
Chill coctel for at least 30 minutes in refrigerator. Serve in bowls or large seafood cups with tostadas, saltines or tortilla chips on the side. A slice of lime is always a must too.