There are so many variations on the Russian beet salad, some with potatoes and dill pickles and other additions, but this one is so simple and fuss-free. Plus, it's a nice seasonal transition salad — served cold, it's refreshing for those still-hot September days, but it also heralds the oncoming fall/winter season of root vegetables.
Preheat the oven to 400 degrees. Wrap the beets in aluminum foil and roast for 1 hour. Remove and let cool off before using a wet kitchen towel or paper towel to remove the skins. Dice and add to a bowl.
Meanwhile, "kill" the onions by covering them with the tablespoon of salt and letting them sit for 10 minutes. This is will mellow out the raw onion flavor. Finally, rinse well and add them to the beets.
Stir in fresh dill with the sour cream and mayonnaise. Season with salt to taste. Best served chilled.