Bring chicken stock and butter to a boil in a thick-bottomed saucepan. Stir in grits and return to a boil. Reduce heat, allowing grits to cook for another 15 minutes at a low boil, and until grits are thick and have absorbed most of the chicken stock. Stir occasionally to keep grits from sticking.
Add ½ cup heavy cream to pot and reduce heat, allowing grits to cook slowly for another 10 minutes. As liquid is absorbed add more cream, cooking grits to the desired consistency. Add salt and pepper to taste with a total cooking time of at least an hour.
The grits should be thick and full-bodied. Fold in chopped garlic, thyme and diced tomatoes. Crumble goat cheese on top. Bake in 350 degree oven for 10 minutes.