Strain lobster shells/cob broth into the Dutch oven, add cream and sherry and bring to a simmer. Stir in potatoes, return to a simmer and reduce heat to a medium-low. Cook until potatoes are tender, about 20 minutes. Stir in lobster meat, salt , pepper, thyme and chives. Cook stirring occasionally until lobster is heated through about 3 minutes. Adjust seasoning as needed.