I am having clam pan roast for dinner tomorrow. What you suggest

I agree with Sam on the corn. That would have been my first thought, and if you have a means to grill it, even better.

Roasted corn on the cob (if you can find it fresh). A corn salad with lime and olive oil, parsley.
Flat bread with herbs. Side salad.
Blanched green beans with rosemary and prosciutto ham: Simmer some olive oil, rosemary and garlic..remove the herbs..cook the ham, cut into matchsticks..and toss with the blanched green beans and top serve at warm/room temp with dusting of bread crumbs, and shaved Parmesan cheese.