Marinated three beans salad by Shawnna and Davide Busetti

This three bean salad is my mom's recipe, and I suspect it has been around a while, because my copy was typed on a typewriter. Three bean salad is a classic American side dish for a reason. It's delicious, it is simple to make, and it is especially ideal for picnics and outdoor gatherings since it doesn't demand refrigeration. There…