In a large bowl, mix ground pork, breadcrumbs, grated onion, minced garlic, smoked paprika, dried sage, egg, Worcestershire sauce, salt, and pepper until just combined, then form into 16 meatballs.
Heat olive oil in a large skillet over medium-high heat and brown the meatballs on all sides, about 6 minutes. Remove and set aside.
Boil peeled and cubed sweet potatoes in salted water until fork-tender, about 12-15 minutes. Drain and set aside.
Deglaze the skillet with bourbon, scraping up browned bits. Add maple syrup, Dijon mustard, and chicken stock, then simmer.
Return meatballs to the skillet, cover, and cook for 8-10 minutes until internal temperature reaches 160°F.
Mash sweet potatoes with butter, heavy cream, cinnamon, nutmeg, and salt until smooth and creamy. Keep warm.
Remove meatballs from skillet and off heat, whisk in cold butter into the sauce until glossy. Season with salt and pepper.
Serve meatballs topped with the bourbon maple sauce alongside the creamy sweet potato mash.