
Combine the shrimp, lime juice, salt, and black pepper in a large shallow bowl or baking dish. Cover and refrigerate for 30 minutes, stirring halfway through to ensure the shrimp is evenly coated.
While the shrimp is “cooking,” heat a large cast-iron skillet or comal over medium heat. Add the guajillo, árbol, and pequín chiles and toast for 1-2 minutes, flipping halfway through, until the chiles are puffed and fragrant. They will darken in color, but make sure not to burn them completely.
Transfer the chiles to a small saucepan. Add enough water to cover them completely and bring to a boil over high heat. Remove the pan from the heat, cover, and let them soak for 10 minutes.
Transfer the softened chiles to a small blender using a slotted spoon. Add the garlic, Jugo Maggi, Worcestershire sauce, and fresh water. Blend until completely smooth.
Pour the chile sauce into the dish with the shrimp and stir until well combined. Cover and refrigerate for an additional 30 minutes.
Stir in the cucumber, mango, red onion, and cilantro until combined. Taste and season with more salt as needed. Serve immediately with tostadas, chips, or saltine crackers.