Prepare your lettuce cups by picking 10-12 of the largest leaves from your head of lettuce. Gently wash them and pat them dry with paper towels; put them aside.
To a large mixing bowl, add the drained tuna, tomatoes, olives, toasted almonds, cucumbers, red onions, and capers. Spritz the juice of half of a lemon over the ingredients and gently toss the ingredients until well mixed.
Spoon the tuna mixture into each lettuce cup, and serve with lemon wedges for extra spritzing.
Tip: To toast your almonds, place them in a dry pan and place them over medium-low heat. Toast them until they are golden brown and aromatic, shaking the pan every so often to avoid burning.