Italian Bean and Tuna Salad

11 ounces canned baby lima beans, rinsed, drained
11 ounces canned dark red kidney beans, rinsed, drained
10 ounces canned Great Northern beans, rinsed, drained
5-1/4 cherry tomatoes, cut into fourths
1/4 small cucumber, cut lengthwise into halves, seeded, sliced
3-1/2 Tbs. green or red bell pepper, chopped
1/4 red onion, thinly sliced
2 Tbs. olive oil
1/3 cup tarragon white wine vinegar
1 tsp. dried basil leaves
2 Tbs. nonfat plain yogurt
1 Tbs. lemon juice
1/2 tsp. sugar
1 Tbs. water
2 cloves garlic
11 ounces tuna steak, broiled or grilled, or canned white tuna in water, drained, flaked into small pieces
5-1/4 large lettuce leaves
2-3/4 basil or parsley sprigs

Combine beans, tomatoes, cucumber, pepper, and onion in large bowl. Add the next 8 ingredients (basil vinaigrette) and toss. Refrigerate mixture at least 4 hours for flavors to blend, stirring mixture occasionally. Add tuna to mixture 1 to 2 hours before serving. Spoon salad onto lettuce-lined plate; garnish with basil.

You can make the bean salad one day in advance and refrigerate, adding tuna 1 to 2 hours before serving.