Rinse the grits in a large bowl of water. With your hand, scoop out any bran or hulls floating on top of the water. Drain well.
Combine the water, salt and butter in a medium saucepan and bring to a boil. Add the grits and stir. Turn the heat to low and simmer for 28 to 40 minutes (check instruction on the bag of grits), stirring occasionally. If the grits stick to the bottom of the pan, reduce the heat and stir more frequently.
Remove from the heat and stir in the cream. Keep warm.
For the shrimp:
While the grits are cooking, peel and devein the shrimp. If desired, swish the shrimp in a bowl of cool, salted water to remove any impurities. Repeat. Finish with a cool water rinse, drain and set aside.
When the grits are ready, prepare the topping. In a large skillet, sauté the shrimp in a tablespoon of butter over medium heat for 1 to 2 minutes, until they are just cooked through. Remove and set aside.
In the same skillet, sauté the country ham and sausage for 1 to 2 minutes, or until the sausage is cooked through.
Add the garlic and cayenne, if using, and sauté 30 seconds. Add the tomatoes and green onions and sauté 30 seconds.
Return the shrimp to the skillet, add water or chicken broth and simmer briefly. Stir in the remaining tablespoon of butter.
To serve, spoon four equal portions of the grits into four bowls. Place 5 or 6 shrimp on top of each portion of grits and spoon on equal parts of the topping, including some of the liquid. Serve at once.