Dissolve steak seasoning in balsamic vinegar, then stir in olive oil. Place pork into a bowl and cover with the marinade. Marinate 2 hours to overnight.
Preheat oven to 180 degrees C.
Place pork into a glass baking dish along with marinade. Bake in preheated oven, basting occasionally until the pork is done; about 1 hour. Let the roast rest for 10 minutes before slicing and serving.