Combine corn, jalapeno, pepper, onion, salt, mustard, cider vinegar, and sugar in a large pot and bring to a boil. Turn heat down to low and simmer for 20 minutes. Chill to 40ºF. Pour into containers, cover and seal.
For the pork:
Dredge pork in rub. Heat oil in a heavy sauté pan over medium heat. Add pork and brown on all sides, about 8 minutes. Transfer skillet to the oven and roast pork until internal temperature is 155ºF. Let rest for a minimum of 5 minutes.
Slice pork 1/2" thick and divide onto 4 plates. Arrange pork slices and jalapeno relish on each plate. Serve with lime wedges and sour cream.