In a large saucepan, combine the bouillon and bay leaf with 1 quart water. Add carrot, potato, celery, onion, 1/4 teaspoon salt, 1/4 teaspoon pepper, and oregano. Bring to boiling; reduce heat. Cover and simmer 10 minutes or till the vegetables are just tender. Add fish, and cook 5 minutes more or till fish is done.
Meanwhile, in a medium saucepan, melt butter or margarine over medium heat. Stir in the flour, 1/2 teaspoon salt, and 1/8 teaspoon pepper till blended. Add milk all at once, and stir till bubbly; remove from heat.
Slowly add the thickened mixture to the fish, stirring constantly. To serve, remove bay leaf. Garnish bowls with fresh parsley.Servings: 4 to 6