Marinate 2 pounds fish in cider for 1 hour. Combine remaining fish with cold water to cover, thyme, and salt and pepper in soup kettle. Simmer, partially covered, 30 minutes. Strain liquid into second kettle. Discard fish. Add vegetables and cook 10 minutes or until tender. Meanwhile, drain cider from fish. Melt butter in frying pan and cook fish over low heat until just tender. Remove broth and vegetables from heat, gently stir in fish. Heat cream in separate pan and add to chowder. Garnish with chopped parsley.