In a large bowl, combine the caraway seeds, garlic powder, smoked paprika and salt. Remove and reserve a third of the spice mix in a separate small bowl. Score the pork shoulder on the cap side with a sharp knife, making 8 shallow cross-cuts. Add the pork shoulder to the large bowl with the spice mix, then rub the entire pork shoulder with the spice mix. Cover with the mustard and let sit for 20 minutes.
In a soup pot, heat the olive oil and vegetable oil on high heat, then add the pork shoulder on the scored-skin side. Sear all sides of the meat to lock in the deep flavor and juices. Add the garlic and thyme. Add the chicken broth, bay leaves and pickle juice and let it simmer, covered, until the meat falls off the bone, 1 1/2 hours. Shred the meat to bite-size pieces in the pot. Add more of the reserved spice mix to taste. Combine 1 tablespoon cornstarch with 1 cup water in a small bowl, adding a bit more cornstarch and whisking together well until you have a "buttermilk" consistency. Pour the cornstarch slurry into the gravy slowly, a little bit at a time, stirring to the desired thickness.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.
Recipe courtesy of Mein Diner Food Truck, Fairbanks, AK