Make the grits: in a medium saucepan, bring Water and Whole Milk to a gentle boil, then slowly whisk in the Stone-Ground Grits along with a pinch of Kosher Salt.
Reduce the heat to low and simmer, stirring occasionally, until the grits are thick and creamy (about 20–30 minutes for stone-ground), then stir in Butter and shredded Sharp Cheddar Cheese until melted and smooth; finish with freshly ground Black Pepper and more Kosher Salt to taste.
Crisp the bacon: in a large skillet over medium heat, cook Bacon until golden and crisp; transfer to paper towels, leaving the rendered fat in the pan and reserving the bacon for garnish (crumble or chop when cool).
Season the Shrimp with a light sprinkle of Kosher Salt and Cajun Seasoning.
Sauté aromatics: add a knob of Butter to the hot skillet with the bacon fat, then add minced Garlic and the white parts of the Scallions; cook briefly until fragrant, about 30 seconds to 1 minute.
Cook the shrimp in the skillet until just opaque and pink, about 1–2 minutes per side depending on size.
Make the pan sauce: pour in Chicken Broth and add a splash of Lemon Juice, a dash of Worcestershire Sauce, and a few drops of Hot Sauce; scrape up any browned bits and simmer until the sauce reduces slightly and becomes glossy.
Finish the shrimp: remove the pan from heat and swirl in another small piece of Butter to enrich the sauce, then fold in the chopped reserved bacon and adjust seasoning with Black Pepper and Kosher Salt as needed.
To serve, spoon the creamy grits into bowls, top with the saucy shrimp, then scatter sliced green Scallions and chopped Parsley over the top for brightness; serve immediately.
