Lowcountry Southern Shrimp and Grits

Bring the water and milk to a boil with the salt. Whisk in the grits. Lower the heat to a simmer and cook, partially covered, until fully cooked and thickened, about 45 minutes. Stir frequently (scrape the bottom and sides!)
TIP: The grits will develop thick, lazy bubbles.
Stir in the butter, a few twists of fresh-cracked black pepper and cheddar cheese, if using.

When the grits are just about fully cooked, heat a medium-sized skillet over low heat. Cook the bacon pieces, stirring occasionally, just until rendered and light brown, about 5 minutes.
While the bacon cooks, lightly dredge the shrimp in flour and sift off any excess.
When the bacon is finished, pour off half of the bacon fat and transfer the cooked bacon to a paper towel-lined plate. Return the skillet to the stove, and raise the temperature to medium-high heat.
Cook the diced onion and tomato paste for one minute, stirring often. Add the shrimp, a generous pinch of salt, pepper, and a few tablespoons of water if the pan looks dry. Cook the onion and shrimp mixture for several minutes, stirring. Add water a tablespoon or two at a time as needed. You want a nice, silky sauce. I use about 1/4 cup water total, but this may vary.
PRO TIP: The shrimp is done when it turns pink and curls. Do not overcook the shrimp.
When the shrimp is just about cooked, add the lemon juice and bacon to the skillet. Stir and cook one minute more. Taste for seasoning.
Spoon grits into shallow bowls. Top with the shrimp and sauce. Garnish with scallions and serve.