Gather your fresh lobster meat, sharp cheddar, Gruyère cheese, ripe avocado, thick sourdough bread, and butter. Ensure that the lobster is cooked and broken into bite-sized pieces. Slice the avocado thinly, and have your butter ready to spread generously on the outside of the bread.

Spread a generous layer of butter on one side of two slices of sourdough bread. On the unbuttered side of one slice, layer the sharp cheddar cheese, followed by the succulent lobster meat, Gruyère cheese, and then the thin avocado slices. Top it with the second slice of bread, ensuring the buttered side is facing outward.

Heat a skillet over medium heat and carefully place the assembled sandwich into the pan. Cook for about 3 to 5 minutes, or until the bottom is golden brown and crispy.

Using a spatula, carefully flip the sandwich to grill the other side. Allow it to cook for another 3 to 5 minutes until golden-brown and the cheese is melted.

Once grilled to perfection, remove the sandwich from the skillet and let it rest for a minute before slicing it in half. Serve immediately.