In a medium saucepan, melt the remaining 1 tablespoon of butter over moderately high heat. Stir in the flour to make a paste. Gradually whisk in the milk until smooth, then bring to a boil, whisking constantly. Simmer over low heat, whisking often, until the sauce is glossy and no floury taste remains, about 5 minutes. Add the cream and simmer for 2 minutes more. Fold in the lobster meat and sherry butter and season with pepper. Blend in the tomalley and roe and simmer until the lobster is cooked through, about 2 minutes longer. Serve with Hot Biscuits on the side.