Begin by peeling, cleaning, and butterflying the jumbo shrimp, then rinse them under cold water. Pat them dry thoroughly using paper towels to ensure they're ready for marinating. At the same time, seed the English cucumber, thinly slice the red onion, and cut the avocado into large dice. Set all prepared ingredients aside for assembly later.

Add half of the mango and 1 habanero pepper (whole) to a blender. Squeeze in the juice from 1 to 2 limes, sprinkle in tajin seasoning and kosher salt to taste. Blend the mixture on high speed until very smooth. Set this puree aside to use later as a flavorful topping.

Roughly chop the remaining habanero and one of the serrano peppers. Transfer the chopped peppers to a molcajete (or mortar and pestle) along with a good pinch of kosher salt. Use the pestle to grind the mixture into a paste—this will be the base for your ceviche marinade. If you want a milder ceviche, remove the seeds from the peppers before grinding.

Pour the cup of fresh lime juice into the molcajete with the chile paste and stir to combine well. Taste and season with more salt as needed. Fold in the prepared shrimp (from Step 1), ensuring every piece is well coated with the marinade. Let the shrimp marinate in the mixture for about 5 minutes to allow the acids to gently 'cook' them. I like to stir every couple of minutes to be sure all the shrimp are evenly exposed to the marinade.

Add the seeded cucumber and thinly sliced red onion (from Step 1) to the marinated shrimp (from Step 4). Dice the remaining half of the mango and add it in as well. Gently fold in the large diced avocado. Mix in as much of the mango-habanero puree (from Step 2) as you like, to reach your desired level of sweetness and heat. Garnish the ceviche with chopped cilantro, and if desired, thin slices of the remaining serrano pepper. For extra crunch and flavor, serve with homemade chips, saltines, or tostadas on the side—I always prefer it with crunchy tostadas!