Russian Monday: “Ukha” – Fish Soup

Name: Russian Monday: “Ukha” – Fish Soup
Ingredients: For the fish stock: Makes 2 quarts; 3 lb. bones and trimmings of white fish (sole, turbot, whiting), cut in pieces; 4 Tbsp. butter; 2 leeks, white parts only, thinly sliced; 1 yellow onion, sliced; 1 cup dry white wine; 1 bouquet garni (a classic bouquet garni consists of a spring of thyme, a bay leaf, parsley stems, and a leek leaf); 2 slices of lemon; 5 black peppercorns; For the ukha soup:; 2 quarts of fish stock; 1 lb. catfish (or cod, snapper); 2 large potatoes, peeled, julienned; 2 medium carrots, peeled, julienned; 1/4 lb. baby portobello mushrooms (optional); 1/2 tsp. smoked paprika; salt and freshly ground pepper; 2 scallions or spring onions, chopped, for serving