Grits, also called Hominy grits, is a southern food made from ground hominy, a vegetable / grain that resembles large corn kernels. It is ground into a paste, boiled until it has a gruel-like consistency, then served with butter and cinnamon.
Ardelia Mathis cooked grits for Benny Russell when he was young. (DS9 novel: Far Beyond the Stars)
in 2268, Leonard McCoy sleepily ordered `Plergb, hafarizz, ungemby... and coffee' (Virginia ham, grits, butter, and coffee) for breakfast from the food synthesizer. The ham and coffee came out looking normal, but his order of grits came out signal-flare orange. He buttered the orange heap and hungrily devoured it regardless of how it looked. (TOS novel: How Much for Just the Planet?)