Rub the pork with salt, pepper, garlic powder and onion powder.
Heat olive oil in a large skillet and sear the pork on all sides until browned (about 3-4 minutes per side).
Make Slow Cooker Base Layer:
While the pork is searing, add the onion, garlic, potatoes and carrots to the bottom of the slow cooker.
Add Slow Cooker Liquid and Pork:
In a small bowl, whisk together the broth, vinegar, soy sauce Dijon mustard, herbs (if using) and 1 1/2 tsp salt.
Pour over the vegetables, stir thoroughly to coat them, then place the pork roast on top.
Add 1/4 cup of water to the pork searing pan and scrape up any browned bits. Pour this into the crockpot, too.
Cook:
Cover and cook on LOW for 9-10 hours or HIGH for 6-7 hours (see notes below). The potatoes and carrots will become tender but hold their shape if cooked low and slow.
Thicken Gravy in the Slow Cooker:
Transfer the cooked pork and vegetables to a plate and cover with foil to keep warm. Spoon as much fat as you can from the remaining slow cooker liquid.
Make a Slurry: In a small bowl, whisk 3 tbsp cornstarch with 3 tbsp cold water until smooth. Pour the slurry into the liquid in the slow cooker. Stir well to combine.
Cover the slow cooker and cook on HIGH for 10-15 minutes, stirring occasionally, until the liquid thickens into gravy.
Serve the pork with the vegetables and drizzle the gravy over the top.
Video
Notes
Use LOW heat setting for the best texture. Collagen needs time to fully break down into gelatin without forcing out moisture too quickly.⚠️High heat does speed up cooking, but it can still break down collagen—just not as gently. The problem is that it also causes muscle fibers to contract more aggressively, squeezing out more moisture.1 tsp pepper is not a casual couple of shakes of a pepper shaker - it's 40 turns on my pepper grinder. It's an important seasoning here, so make sure you use the full amount!