Combine canned tuna with chickpeas, diced cucumber, cherry tomatoes, and avocado. Dress with olive oil, lemon juice, salt, and pepper. You can also add a handful of greens like spinach.
Nutrients: Protein (tuna), healthy fats (avocado), fiber (chickpeas), vitamins (vitamin C from tomatoes and cucumber), minerals (potassium and magnesium from avocado).