In a large bowl, combine the ground pork, breadcrumbs, grated onion, minced garlic, smoked paprika, dried sage, egg, Worcestershire sauce, salt, and pepper. Gently mix the ingredients until just combined, then form the mixture into 16 golf-ball-sized meatballs.

Heat olive oil in a large skillet over medium-high heat. Add the meatballs and cook, turning occasionally, until they're beautifully browned on all sides, about 6 minutes. Transfer the meatballs to a plate and set aside.

While the meatballs are browning, place the peeled and cubed sweet potatoes in a pot, cover with salted water, and bring to a boil. Simmer the sweet potatoes for 12-15 minutes, until they're fork-tender. Drain the potatoes and set them aside.

Return the skillet to medium heat and deglaze it with the bourbon, scraping up any browned bits from the bottom of the pan. Add the maple syrup, Dijon mustard, and chicken stock, and bring the mixture to a simmer. Return the meatballs to the skillet, cover, and cook for 8-10 minutes, until the meatballs reach an internal temperature of 160°F (71°C).

In a separate bowl, mash the cooked sweet potatoes with butter, heavy cream, cinnamon, nutmeg, and salt until the mixture is smooth and creamy. Keep the sweet potato mash warm while you finish the sauce.

Remove the meatballs from the skillet and transfer them to a plate. Off the heat, whisk the cold butter into the bourbon-maple sauce until it becomes velvety and glossy. Season the sauce with salt and pepper to taste.

Spoon the creamy sweet potato mash onto plates and top with the tender pork meatballs. Generously drizzle the rich bourbon-maple pan sauce over the top.