In a small mixing bowl, mix together mustard, garlic, honey, herbs (rosemary, thyme, sage), vinegar, and salt and pepper. Set aside.

Add cooking oil to a large pan and bring to medium-high heat. Sear the pork for 3 minutes on each side or until golden brown. Transfer the seared pork to a slow cooker. Pour the mixture over the pork, coating it, and set to low. Allow to cook for 4-5 hours, flipping over halfway through, so the juices evenly soak.

When ready, transfer pork to a cast iron pan (or broiler safe pan). Pour remaining juices from slow cooker into a medium saucepan and bring to medium-high heat. Add corn starch (or flour) to thicken and whisk until dissolved.

Preheat oven to broil setting. Use a brush to coat the meat with the thickened sauce mixture, then transfer to the oven to broil for about 3-5 minutes or until the sauce starts to bubble. Remove from oven, garnish with herbs, and serve! (Unused portion of sauce can be served as a gravy to pair with mashed potatoes or other seasonal sides.)