This is Day 15: Lunch, on the 21 Day Wonder Diet. You can make the filling the night before, and assemble the sandwich in the morning. The baby spinach will stop the bread going soggy. This lunch is to be followed by an afternoon snack of 1 small apple.
- Combine tuna, celery, onion, dill and capers in medium bowl.
- Divide half the spinach between two bread slices; top with tuna mixture, then remaining spinach and bread.