Start the Traeger on Smoke with the lid open until the fire is established (4-5 min).
Place the corned beef brisket, fat side up on the grill and smoke on the Smoke setting for 3 hours.
After 3 hours, turn the heat up to 250 degrees F and pre-heat for 10-15 minuntes.
While the corned beef is smoking, dice 2 russet potatoes and in a sautee pan with vegetable oil, sprinkle w/ salt & pepper and sautee until golden brown.
Add finely diced onions and combine.
Turn heat to low and cover for 20 minutes until soft.
Shred the corned beef and add to the potatoe & onion mixture.