Doesn’t sound like such a problem, but it’s clearly a meal crying out for something green. The conservative approach would be to fix a salad, and with such exceptional produce available these days, that would not be a bad choice. Something a little more distinctive, such as sautéed snow peas or some wilted greens, would be another option.
We always enjoy cold fruit soups at this time of year, too, and while melons may be out, a peach or cherry soup as a first course probably wouldn’t overextend any of your guests, and they’re easy to make. If you don’t like the soup idea, a favorite dessert for us is a berry tart, with a shortbread crust, a thin layer of melted white chocolate, and blueberries on top of that.