Combine ground pork, breadcrumbs, grated onion, minced garlic, smoked paprika, dried sage, egg, Worcestershire sauce, salt, and pepper gently in a large bowl until just mixed; form into 16 meatballs.
Heat olive oil in a skillet over medium-high heat; brown meatballs on all sides for about 6 minutes. Remove and set aside.
Boil peeled and cubed sweet potatoes in salted water until tender, about 12-15 minutes; drain and set aside.
Deglaze skillet with bourbon over medium heat, scraping browned bits; add maple syrup, Dijon mustard, and chicken stock, then simmer.
Return meatballs to 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; keep warm.
Remove meatballs, whisk cold butter into sauce off heat until glossy; season sauce with salt and pepper.
Serve meatballs with sweet potato mash and bourbon-maple sauce.