My recipe is similar- my Mom called it Italian Mushroom salad. She used mushrooms (fresh are awesome) celery, roasted red peppers in the jar, black olives and her Italian dressing. We let it marinate for awhile.
You can get creative with this too. I like the chick pea idea.
I've made this for a lot of events and people really like it. It's very refreshing and also colorful.