I went to Gastronom yesterday evening hoping to try "cherry-cheese", but was either too late or went on the wrong day, so I sampled a few other items:
Puff pastry "dumpling" stuffed with feta and spinach - I reheated this in my toaster oven at home. Very tasty. The filling was pretty dry, but that was OK because then the puff pastry wasn't soggy.
Stuffed cabbage - Ground meat filling in tomato sauce. Reheated these in the microwave and liked them a lot. I think they must put sausage in the filling because it was pink.
Cherry-stuffed bun - This was an oval baked bun of sweet egg dough (dotted with raisins) encasing a cherry filling. It was not overly sweet and was good for breakfast. Very tasty in a homey way, like something your Russian grandmother would bake.
They had a few other pastries, including cherry turnovers and cheese turnovers, but no cherry-cheese. There were also a few different meat-filled pastries, including some very greasy-looking piroshki. I didn't try them because I don't care much for fried piroshki - I prefer the kind baked in sheets (like my mother used to make).
The people at Gastronom were very friendly. I will definitely go back and try more from their deli case. They also have a nice selection of smoked fish and sausages (mostly unlabeled).