Peel the garlic and mash with a fork; work it into the butter. Gradually add the rest of the herbs and seasonings. Mix in the crumbs and sherry. Arrange the cooked shrimp in buttered individual ramekins and top with the mixture. Bake in a 450-degree oven for 5-8 minutes, or until thoroughly hot and bubbly, or run under the broiler for 2 or 3 minutes.