In a small bowl, mash half of a ripe avocado using a fork. Add one teaspoon of freshly squeezed lemon juice, along with a pinch of salt and pepper to taste. Stir until the mixture is smooth and creamy.

Grab two slices of sourdough or artisan bread and spread a thin layer of mayonnaise on one side of each slice. Place one slice mayo-side down on a clean surface. Spoon the creamy avocado mixture onto this slice, followed by half a cup of cooked shredded chicken, layering generously. Finish with two slices of cheese before placing the second slice of bread on top.

In a skillet, heat one tablespoon of butter over medium heat until it melts and begins to bubble. Gently place the assembled sandwich in the skillet and cook for 3-4 minutes, pressing down lightly with a spatula.

Carefully flip the sandwich using your spatula and grill the other side for another 3-4 minutes until golden brown and the cheese melts.

Once both sides are perfectly toasted, remove it from the skillet and let it cool for a minute before slicing it in half. Serve warm.