Jalandhar's food is straight Punjabi: heavy on dairy, slow-cooked, and not subtle. The classic local dishes are sarson da saag with makki di roti (mustard greens with maize flatbread), Amritsari kulcha, butter chicken, and a long roster of paneer dishes. Sweets — pinnis, ladoos, gulab jamun, peda — are taken seriously.
Bhojan Bhandar in Ladowali Road is a long-running pure-vegetarian thali restaurant that does the classic Punjabi spread well at modest prices. Haveli, on the GT Road bypass on the way to Phagwara, is a tourist-aimed but genuinely good Punjabi village-style restaurant with live music and a wide menu (popular for weddings; book ahead at weekends). Mahajan Sweets in the bazaar near Devi Talab is the source for pinnis (winter), barfi, and good gulab jamun. Punjabi Rasoi near the bus station does fast, cheap chole bhature and aloo paratha breakfasts; come hungry.
For Amritsari-style fried fish, try the small stalls on Bhagat Singh Chowk in the evenings — Punjabis from across the Doaba come here for it.