Heat a large skillet or grill pan over medium-high heat. When hot, add the shrimp in a single layer (no extra oil is needed if your pan is nonstick; otherwise use just a light wipe of oil).
Cook the shrimp for about 1–2 minutes on the first side, until they turn pink and lightly browned in spots, then flip and cook another 1–2 minutes, just until opaque and firm. Do not overcook or they’ll turn rubbery.
Transfer the cooked shrimp to a plate and let them cool for a few minutes until they’re warm but not piping hot. This keeps the avocado from getting too soft and runny.
To assemble, arrange small dollops of the mashed avocado mixture on a serving platter, using about 1 heaping tablespoon per bite. You can use a spoon or pipe it through a plastic bag with the corner snipped off if you want a fancier look.
Set one shrimp on top of each avocado dollop, curved side up so the pink color shows nicely. Press very gently so the shrimp nestles into the avocado and doesn’t slide around.
Serve right away for the best texture, or cover the platter loosely and chill for up to 1 hour before serving. If chilling, let the bites sit at room temperature for 10–15 minutes before putting them out so the flavors soften and bloom.
