1. Drain tuna completely, pressing gently. Break into large chunks rather than shredding.

2. Drain and rinse cannellini beans thoroughly under cold water for 30 seconds minimum. Let drain in colander.

3. Dice vegetables uniformly (1/4-inch pieces). If using red onion, soak in cold water 5 minutes to mellow, then drain and pat dry.

4. Make dressing: In small bowl or jar, combine olive oil, lemon juice, minced garlic, Dijon mustard, oregano, salt, pepper, and red pepper flakes if using. Whisk or shake until emulsified.

5. In large mixing bowl, gently combine drained beans, tuna chunks, diced red onion, halved cherry tomatoes, and diced cucumber. Fold gently to keep tuna and beans intact.

6. Fold in chopped parsley and basil if using.

7. Pour dressing over salad and fold everything together gently but thoroughly until evenly coated.

8. Add optional ingredients (olives, capers, feta, avocado, nuts) and fold in last. Add avocado just before serving.

9. Taste and adjust seasoning with more lemon, salt, or olive oil as needed.

10. Let rest 5-10 minutes if time allows for flavors to meld, or serve immediately.

11. Serve over greens, in pita pockets, on crostini, or as is for a complete meal.