Using a 9" cast iron skillet, add the diced bacon and diced Jalapeño. Cook over medium heat until bacon is crispy (~8-10 minutes).
Transfer the bacon and jalapeños to a paper towel and pat dry. Drain the bacon grease from the skillet and set aside.
In a medium sauce pan, bring the heavy cream, chicken broth, and water to a boil over medium-high heat. Once boiling, slowly whisk in the grits. Reduce heat to medium-low, cover and cook for 5-7 minutes, or until grits have thickened and absorbed the liquid.
Stir in the bacon, jalapeños, salt and 1 1/2 cups of the grated cheese.
Transfer the grits into the cast iron skillet and top with the remaining 1/2 cup of grated cheese. Place skillet under broiler for 3-5 minutes, or until cheese on top has melted and grits are light brown in color. Garnish with green onions (optional).