Preheat NESCO® Roaster Oven to 400ºF. Lightly wipe cookwell with cooking oil. Add margarine; cover, cook until melted. Arrange pork roast in preheated cookwell. Cover; roast 10 minutes. Reduce temperature to 325ºF. Combine remaining ingredients. Remove rack with meat to a heatproof surface. Spread mustard mixture over roast.
When melted and fragrant, sear the pork shoulder roast on all sides for 2-3 minutes or until brown. Slow Cook: Line a baking sheet or roasting pan with tin foil. Then place a wire rack on top. Transfer the seared pork shoulder roast on top of the wire rack and bake at 250ºF for 7-8 hours, depending on how big your pork roast is.
DIRECTIONS Preheat electric roaster oven to 400. Lightly wipe cookwell with cooking oil. Add margarine; cover, cook until melted. Arrange pork roast in preheated cookwell. Reduce temperature to 325ºF. Combine remaining ingredients. Remove rack with meat to a heatproof surface. Spread mustard mixture over roast. Set rack in cookwell.
Place in a large roasting pan skin side up. Roast uncovered in a preheated 500 degree (F) oven for 20 minutes. Reduce heat to 300 degrees and roast for an additional 45 minutes per pound. Total cooking time for an 8lb roast should be about 6 hours and 20 minutes. Remove the pork roast from the oven and let rest for 30 minutes.