Would suggest 2 days in Amritsar and 2 in Chandigarh.
Places to visit in Amritsar
4)Kesar da Dhaba for food
5)Bhrawan da Dhabad for food
6)Amristsari Chhole Kulche Places to visit in Chandigarh
3)Sukhna Lake for boating
4)Pinjour or Kalka tour if you have time though it would not be Punjab
5)Naina Devi temple if you have time...again its not Punjab.