To serve this make-ahead meal family style, spread the Parmesan grits and greens on a wooden board or oversize platter placed in the center of your table. Top with pulled pork and garlicky sautéed mushrooms. Use your slow cooker to keep the grits warm until you’re ready to serve. The pork can be made up to two days ahead and reheated in a skillet.
Mince 1 garlic clove, and set aside. Halve remaining 8 cloves. Make 16 small, deep cuts in roast, and insert garlic halves. Stir together granulated sugar, Italian seasoning, 2 teaspoons of the salt, and 1 1/2 teaspoons of the black pepper. Place pork in a large bowl; rub with sugar mixture. Cover and chill 8 to 24 hours.
Preheat oven to 325°F. Place pork on a rack in a roasting pan, and bake in preheated oven until meat shreds easily with a fork, 4 to 4 1/2 hours.
Meanwhile, stir together water and grits in a lightly greased 3- to 4-quart slow cooker. Let stand 2 minutes, allowing grits to settle to bottom; tilt slow cooker slightly, and skim off solids using a fine wire-mesh strainer. Cover and cook on HIGH until grits are tender and thickened, 2 1/2 to 3 hours, stirring every 45 minutes. Add cream and grated Parmesan, and whisk until cheese is melted. Stir in 1 teaspoon of the salt and 1/4 teaspoon of the pepper. Cover and keep warm.
Remove pork from oven; let stand 15 minutes. Shred pork with 2 forks. Heat 1 tablespoon of the oil in a large skillet over medium-high. Add kale, and cook, stirring constantly, until wilted and tender, about 3 minutes. Stir kale into grits. Wipe skillet clean.
Heat remaining 2 tablespoons oil in skillet over medium-high; add mushrooms and shallot, and cook, stirring constantly, until golden, 5 to 7 minutes. Add minced garlic, and cook 1 minute.
Add chicken stock and shredded pork, stirring and scraping to loosen browned bits from bottom of skillet. Cook until pork is thoroughly heated, about 3 minutes. Sprinkle with chopped fresh parsley and remaining 1/2 teaspoon salt and 1/4 teaspoon black pepper. Spread warm grits on a large wooden board or warm piece of marble. Top with pork mixture. Garnish with crushed red pepper and additional Parmesan, if desired.