Preheat pellet grill to 350 °F.
Grill sausage links on the preheated grill for 10-15 minutes or until heated through.
Remove the sausage links from grill and cut them into 1-inch pieces.
Spray a 9'' ×13'' tin pan with non-stick spray. Spread out hash browns on bottom of pan. Top with sausage pieces.
Combine eggs, salt, pepper, 1 c. cheese, onions, and milk in a bowl. Pour the mixture over sausage and hash browns. Then top with the remaining 1/2 c. of cheese.
Transfer the tin pan to the grill grate, and grill at 350 °Ffor 45 minutes or until the middle is set.