Steps
1. Start by buttering one side of each slice of bread.
2. Heat a skillet over medium heat and toast the bread, buttered side down, until golden brown.
3. In the same skillet, fry the egg to your liking (sunny-side up or over easy).
4. Spread mayonnaise on the unbuttered side of each slice of bread.
5. Layer the grilled chicken slices on one slice of bread.
6. Add the fried egg on top of the chicken, followed by the cheese slice, allowing it to melt slightly.
7. Top with avocado, salad greens, tomato, and cucumber. Season with salt and pepper.
8. Close the sandwich with the other slice of bread, mayonnaise side down.
9. Slice in half and serve immediately.