You’ll want to consider a few things when you are determining if any food can be eaten on the Keto Diet. The first thing to ask is, “Is it processed?” If the item in question contains pure ingredients, then proceed to step two. Next, do a search of the nutrition information on your desire food or dish. A quick google search tells me that Solyanka contains: 171 Calories Per 1 Cup Serving. It also contains: 11.32g Fat, 4.17g Fat, and 12.69g Protein. With all of the different meats in the ingredient list, it definitely makes this a protein heavy dish. I would recommend removing the potatoes (can you substitute them), adding some fat (MCT Oil? Avocado?Butter?) and cutting out some of the proteins to balance this meal a bit more.
All in all, it is ok to eat, but you will be using about a quarter of your daily carbs. You will also need to balance this meal with more fat to keep it keto.