Combine beef, salt, pepper, garlic and about 6 cups (1 1/2 liter or about 1 1/2 quarts) boiling water in a large saucepot.
Cover; bring to boiling; lower heat and simmer until meat is almost tender.
Meanwhile, lightly brown onion, carrot and potato in several tablespoons butter; add to saucepot and bring to boiling; add cabbage.
Cook until meat and vegetables are tender; add tomatoes, beets (with cooking liquid) and vinegar; season soup to taste and heat thoroughly.
Garnish with parsley and serve with sour cream.
To make Kasha: Brown the buckwheat groats in 2 or 3 tablespoons (30 or 40 grams or 1 or 1 1/2 ounces) butter or margarine in ovenproof casserole or baking dish.
Add enough boiling salted water to cover buckwheat; cover tightly and bake in a moderate oven (350°-375°F or 180°-190°C) until done.
Add more water, if needed, during baking.