Mix the shrimp and melted butter in a bowl until well combined. Heat a skillet over medium-high heat for a few minutes until it hot. Add the shrimp to the skillet in one layer, and fry it for a minute or until it starts to turn pink around the edges, then flip it over and cook it until the shrimp are tender in less than a minute. Transfer the shrimp to a plate when finished cooking. Let it cool while preparing the other ingredients.
Salad mixing: Pour all other ingredients (avocado, tomato, feta cheese, coriander, lemon juice, olive oil, salt, and pepper) into a large mixing bowl until well combined. Then add shrimp. Season it with salt and pepper then serve it.