These grits can be cooked either on the stovetop or in the slow cooker. Either preparation method yields an incredibly creamy grit and these same methods work for packaged dry polenta as well.
Spray the insert of a slow cooker with cooking spray (clean up is a cinch with this simple trick) and preheat the crock pot on high while you get the grits started.
In a medium saucepan, add the milk, 1 cup half-and-half, 1 tablespoon butter, and grits. Season with salt and bring to a boil over medium-high heat, whisking constantly to keep the mixture lump-free. Boil for 2 to 3 minutes. Pour the mixture into the slow cooker and cook on high for 2 hours, stirring once or twice per hour. Once you are ready to serve, open the slow cooker and whisk in the remaining 1 tablespoon butter and the remaining 1/3 cup half-and-half.
Creamy Stove top Method:
In a medium saucepan, add the milk, 1 cup half-and-half, 1 tablespoon butter, and grits. Season with salt and bring to a boil over medium-high heat, whisking constantly to keep the mixture lump-free. Boil for 2 to 3 minutes. Cover with a tight fitting lid and reduce heat to a simmer and cook for another 20 to 25 minutes stirring occasionally. Once you are ready to serve, whisk in the remaining 1 tablespoon butter and the remaining 1/3 cup half-and-half.
The stove top method may take a little more liquid than the crock pot method due to evaporation.