Easy Tuna Avocado Sandwich (5-minute high-protein lunch)

1 In a small bowl, combine the drained tuna, mayo, lemon juice, chopped capers, dried dill, sea salt, and black pepper. Mix well until creamy and evenly combined. Taste and adjust seasoning if needed.
2 Toast the sourdough slices until golden and crisp. Spread a generous layer of the tuna mixture onto one slice of toast. Top with sliced avocado and tomato, then finish with the second slice of toasted sourdough.
3 Slice and enjoy immediately while the bread is still warm and crisp.