Try Sitaram Diwan Chand in Paharganj/Chandni Chowk for famous chole bhature (opens ~8am) or Saravana Bhavan in Connaught Place for South Indian staples.
Visit Red Fort (typically 9:30–16:30; closed certain days — check before visiting) and then stroll/drive through Chandni Chowk and Jama Masjid for Old Delhi flavor.
Drive 20–30 min to Kufri for valley views and a visit to the Himalayan Nature Park (open approx 9:00–17:00) — ideal for short treks and horse rides in winter-permissible areas.
Visit the stately buildings and gardens around the Vice Regal Lodge and take photos from public viewpoints (check visiting hours, usually daytime only).
Visit Solang Valley (paragliding/winter sports depending on season); note that Rohtang Pass is usually closed in winter (Nov–Mar) — check local travel advisories.
Catch an overnight Volvo/taxi toward Chandigarh or a night train/coach towards Delhi to position yourself for the Agra leg; overnight travel saves daytime.
Board the fast service to Agra; travel time is short, so you can reach Agra by late morning for a half-day visit (best to plan Taj for sunrise next morning, see Day 9).
Visit the Taj Mahal at sunrise for the best light and fewer crowds — Taj timings: generally sunrise–sunset; closed on Fridays for prayers — buy tickets in advance.