Prep the produce: Halve the tomatoes, dice the cucumber, and thinly slice the red onion. Chop the parsley and dill. Halve the olives and chop the roasted red peppers if using.

Mix the dressing: In a small bowl, whisk together lemon juice, lemon zest, olive oil, Dijon, garlic, red wine vinegar (if using), oregano, a pinch of salt, and a few grinds of pepper. Taste and adjust acidity or salt.

Drain the tuna: If using oil-packed tuna, lightly drain but don’t press it dry—the oil adds flavor. If using water-packed, drain well.

Combine in a bowl: Add tuna to a large bowl and gently break it into bite-size chunks. Add tomatoes, cucumber, onion, olives, capers, roasted red peppers, and herbs.

Toss with dressing: Pour the dressing over the salad and toss gently until everything is coated but the tuna still holds texture.

Add feta (optional): Fold in crumbled feta. Taste and season with more salt, pepper, or lemon as needed.

Rest briefly: Let it sit for 5–10 minutes so the flavors can mingle. Serve with greens, pita, or crusty bread.