Steps
1. In a bowl, combine the drained tuna, mayonnaise, chopped pickles, pickle juice, and Dijon mustard.
2. Mix well until all ingredients are evenly incorporated.
3. Season with salt and pepper to taste.
4. Toast the bread slices lightly.
5. Place the lettuce leaf on one slice of bread.
6. Spread the tuna pickle mixture evenly over the lettuce.
7. Top with the second slice of bread.
8. Cut the sandwich diagonally and serve immediately.