Steps
1. Toast the slices of whole wheat bread.
2. Spread mayonnaise evenly on one side of each slice.
3. Layer avocado slices, cucumber, tomato, and shredded lettuce on one slice of bread.
4. Season with salt and pepper.
5. Place the second slice of bread on top to complete the sandwich.
6. Cut the sandwich in half diagonally.
7. Serve and enjoy!