In a small bowl, whisk together the honey, Dijon mustard, and kosher salt until smooth and well combined. Taste and adjust the salt if needed; the mixture should taste balanced and slightly salty-sweet.
Pour the honey mustard mixture evenly over the pork roast, turning the roast once or twice with tongs to coat all sides. Position the roast fat side up if there is a fat cap, so it bastes the meat as it cooks.
Cover the slow cooker with the lid and cook on LOW for 7 to 9 hours, or on HIGH for 3 1/2 to 4 1/2 hours, until the pork is very tender and easily shreds with a fork. The sauce will darken and become a glossy golden color with some caramelized edges around the roast.
Once cooked, carefully transfer the pork roast to a cutting board. Let it rest for about 10 minutes, then slice or shred the meat, depending on how you want to serve it.
