Make the Limeade Chillers: Add the frozen limeade concentrate to a pitcher. Pour in the cold water and sweetened condensed milk, then whisk until smooth and fully combined. Refrigerate while preparing the salad.
Prepare the Tostada Topping: Add the tortilla chips and shredded extra-sharp cheddar cheese to a food processor. Pulse until the mixture forms coarse crumbs.
Bake the Topping: Line a baking sheet with aluminum foil and spread the tortilla-chip and cheese mixture into a thin, even layer. Bake at 375°F for about 8 to 10 minutes, until the cheese is melted and the mixture forms a crisp sheet. Remove from the oven and let cool.
Heat the Skillet: Add the olive oil to a large skillet and heat over medium-high heat.
Cook the Peppers: Add the sliced mini sweet peppers and cook for about 2 minutes, stirring occasionally.
Add the Red Onion: Stir in the sliced red onion and cook for another 2 to 3 minutes, until the vegetables begin to soften.
Add the Corn: Stir in the fresh corn kernels and cook for about 1 minute.
Add the Olives: Add the sliced black olives and stir to combine. Cook for about 1 minute.
Season the Shrimp: Place the raw shrimp in a medium mixing bowl. Sprinkle with the taco seasoning and toss until the shrimp are evenly coated.
Cook the Shrimp: Add the seasoned shrimp to the skillet with the vegetables. Cook over medium-high heat for about 4 to 5 minutes, stirring occasionally, until the shrimp are opaque and cooked through.
Prepare the Salad: Place the shredded lettuce and chopped cilantro in a large mixing bowl.
Dress the Salad: Pour the cilantro-avocado dressing over the lettuce and cilantro. Toss with tongs until everything is evenly coated.
Prepare the Chillers: Divide the ice among four drinking glasses. Pour the chilled limeade mixture over the ice.
Break the Tostada Topping: Once cooled enough to handle, break the baked tortilla-cheddar sheet into rough, crispy pieces.
Assemble the Salad: Transfer the dressed lettuce to a serving platter. Spoon the warm shrimp and vegetable mixture over the lettuce.
Finish and Serve: Scatter the crispy tortilla-cheddar pieces over the salad just before serving. Serve immediately with the limeade chillers.