- Begin by making the tuna mayo.
- Mix together the tuna, mayonnaise and capers in a bowl.
- Add lemon zest to taste.
- Finely chop the leek and add in.
- Season to taste with salt and pepper.
- Add lettuce to the bread.
- Add the tuna mayo and serve.
Tip: Make a larger batch of tuna mayo and keep covered & refrigerated, so your next sandwich will be ready in a flash!