Balsamic vinegar is available at specialty foods stores, Italian markets and some supermarkets.
Directions
Combine first 6 ingredients in medium bowl. Season with salt and pepper. Let stand 30 minutes, tossing occasionally.
Bring water and salt to boil in heavy medium saucepan over medium-high heat. Gradually add cornmeal, whisking until smooth. Reduce heat to low. Add corn kernels and stir until polenta is very thick, about 10 minutes.
Spoon polenta onto plates. Top with salad mixture and serve.