Mediterranean tuna salad

4 (6 oz) cans albacore tuna, drained well
1 (14-oz) can quartered artichoke hearts, drained
1/2 cup chopped red bell or piquillo peppers
3/4 cup sliced Greek olives
1/2 small red onion, finely chopped
1/4 cup chopped flat-leaf parsley
1/4 cup chopped basil
2 cloves garlic, finely chopped
1 tsp dried or 1 tbsp chopped fresh oregano
1/2 cup mayonnaise
3 tbsp lemon juice
Salt and freshly ground pepper to taste