Tarragon Fish Soup with Seared Black Cod

Ingredients:
1 3/4-2lbs true cod, fresh (ling cod or sea bass can be used)
1/2 lb. black cod
2 large shallots
1 head garlic
3 Tablespoons chicken bouillon (“Better Than Bouillon”)
2 1/2 cups Nigori unfiltered sake (pinot grigio can be used)
1 bunch tarragon
1 pint heavy cream
1 Tablespoon butter
Fresh pepper to taste