Chopped Salad with Grapes and Mint

1 heart of romaine, coarsely chopped

1 pint grape tomatoes, halved

1 medium seedless cucumber, peeled and cut into 1/2-inch dice

1 small red onion, cut into 1/4-inch dice

1 cup corn kernels

1 cup diced cooked chicken

1/2 cup halved green grapes

3 ounces feta cheese, crumbled (1/2 cup)

3 tablespoons extra-virgin olive oil

2 tablespoons finely chopped mint

2 tablespoons finely chopped basil

2 tablespoons red wine vinegar

1 tablespoon fresh lime juice

Salt and freshly ground pepper