Wild and Brown Rice Salad

olive oil

balsamic vinegar

coarse salt

freshly ground black pepper

Dijon mustard

cooked wild rice, made according to package directions; 3 cups cooked brown and/or brown basmati rice (about 1 1/3 cups uncooked), made according to package directions

yellow bell pepper, cut into 1/2-inch pieces

red onion, finely chopped

stalks celery, cut into 1/2-inch pieces

seedless cucumber, quartered lengthwise and cut into 1/4-inch slices

red cherry tomatoes, quartered