All in all, the food in Russia is not good. At least not to my palate, and I'll pretty much try anything. The food is bland and repetitive.
Bistro Garcon is a true find in St. Petersburg. Everything on the menu is wonderful, but be careful, some dishes can be a little rich if you're used to light fare.
I ate breakfast here every day, and had came back for lunch or dinner (or both) most days too. The waitstaff is effecient and polite (when I went there was even a near-sighted waiter who inadvertently provided some light comedy), but not terribly fluent in English. Don't worry, you'll get your point across. I can't recommend this restaurant highly enough. Order some onion soup, sit back, and enjoy.