Cucumbers! Napa cabbage! Sweet new onions! Crunchy, cooling produce is abundant just in time for the heat, and Summer is indeed the perfect time for this simple, sweet and tangy salad. This is a great side dish for fish, chicken or even grilled steak, and you can easily double it up for a crowd. If you can’t find uncured onions at your farmers market or CSA, seek out a sweeter variety of white onion.