In a heavy-bottomed saucepan, bring the chicken broth, milk, and salt to a gentle simmer over medium-high heat.

Gradually whisk the stone-ground grits into the simmering liquid in a slow, steady stream. Whisk continuously for 2 minutes to prevent lumps from forming.

Reduce the heat to the lowest setting, cover, and simmer. Uncover and whisk vigorously every 5 minutes until the grits are thick, creamy, and tender.

Remove the grits from the heat. Stir in the butter, heavy cream, and cheddar cheese (if using) until melted and smooth. Cover to keep warm.

While the grits are cooking, heat a large cast-iron skillet over medium heat. Add the chopped bacon and cook until crisp and the fat has rendered. Use a slotted spoon to transfer the bacon to a paper towel-lined plate, leaving the bacon grease in the skillet.

Add the diced andouille sausage to the bacon fat. Cook until browned, then remove with a slotted spoon and set aside with the bacon.

In the same skillet with the remaining fat, add the onion, bell pepper, celery, and the white parts of the green onions. Sauté until the vegetables are softened. Add the minced garlic and cook for 1 more minute until fragrant.

Sprinkle the flour over the vegetables and stir constantly for about 1 to 2 minutes to cook out the raw flour taste and create a light roux.

Gradually whisk in the chicken broth, ensuring there are no flour lumps. Bring to a simmer and let it thicken slightly to form a gravy.

Toss the shrimp with the Cajun seasoning. Add the shrimp to the simmering gravy and cook until they just turn pink and opaque.

Stir the cooked bacon, andouille sausage, lemon juice, and hot sauce into the skillet. Simmer for 1 minute to warm everything through. Taste and adjust seasoning with salt and pepper if necessary.

Divide the warm, creamy grits among shallow bowls. Spoon the shrimp, sausage, and gravy generously over the grits. Garnish with the remaining green onion tops.