For the beet stock:
6 cups water
1 large onion, chopped
1 pound beets (about 2 medium beets), peeled and grated
1 medium carrot, peeled and grated
4 stalks of celery, trimmed and chopped
2 Beefsteak or Jersey tomatoes, chopped
3 whole allspice berries
2 teaspoons dill seeds
1 fresh bay leaf
2 or 3 sprigs of parsley
2 or 3 sprigs of dill
1 sprig of thyme
For the Soup:
1 tablespoon canola oil
1 bunch Tuscan kale or chard, thick stems removed, cut into ribbons
1 carrot, grated
1/4 head of green cabbage, trimmed and thinly sliced
Diamond Crystal kosher salt and freshly ground black pepper
Lemon juice, for serving
Crème fraîche, for serving
Make the beet stock:
Combine all the stock ingredients in a large pot and bring to a boil; reduce the heat and simmer, covered, for 1 1/2 to 2 hours.
When the stock is cool enough to handle, strain it through a fine mesh sieve, pressing down on the mixture to extract all the liquid.
Discard the solids and set the stock aside; it can be stored in the refrigerator for up to a week.
Make the Soup:
Pour the oil into a large pot; place it over medium heat and add the kale, carrot, and cabbage.
Cook, stirring frequently, until the kale and cabbage are al dente.
Pour the reserved stock into the pot and stir.
Season with salt and pepper to taste.
Serve the borscht hot; finish each bowl with a squeeze of lemon juice and a little crème fraîche.