Prep the pork. Pat the pork dry with paper towels and trim excess fat if desired.
Cut a shoulder roast into 2–3 large chunks for even cooking. Season lightly with black pepper.
Brown the meat (optional but recommended). Heat the neutral oil in a skillet over medium-high. Sear the pork on all sides until deeply browned, about 2–3 minutes per side.
Transfer to the slow cooker.
Layer the aromatics. Scatter the sliced onion in the bottom of the slow cooker if not already added. Place the pork on top.
Mix the sauce. In a bowl, whisk honey, soy sauce, chicken broth, vinegar, minced garlic, ginger, sriracha (if using), and sesame oil. Taste and adjust: add a bit more vinegar if it tastes too sweet, or honey if you want sweeter.
Cook low and slow. Pour the sauce over the pork.
Cover and cook on LOW for 7–9 hours (best for shoulder) or HIGH for 4–5 hours. For pork loin, check at the earlier end to avoid overcooking.
Check for tenderness. The pork should be very tender and easy to pull apart with two forks. If it’s not, cook another 30–60 minutes and check again.
Reduce and thicken the sauce. Transfer the pork to a plate and tent with foil.
Skim excess fat off the liquid if needed. Whisk together cornstarch and cold water, then stir into the sauce. Cover and cook on HIGH for 10–15 minutes until thick and glossy, or simmer in a saucepan on the stove for faster results.
Shred or slice. Shred the pork into large chunks or slice if you used a loin.
Return the meat to the slow cooker and toss with the sauce.
Garnish and serve. Sprinkle with sesame seeds and green onions. Serve over rice, mashed potatoes, or with steamed greens and roasted veggies.