Swiss Chard Tuna Salad with Egg

We have a forest of Swiss Chard growing and found a great recipe online.  We modified it a bit:

1/2 cup mayonnaise

1 teaspoon dijon mustard

2 teaspoons balsamic vinegar

1/2 cup chopped kalamata olive

2 teaspoons brine from the olives

2 6-ounce cans tuna, drained

3/4 cups chopped Swiss chard stems

2 to 3 cups chopped Swiss chard leaves

1/4 cup chopped fresh parsley

                                         1 cup chopped green onions

                                         4 hard boiled eggs, cubed

                                         Salt & pepper to taste

                                         Serves 4