It’s hard to find standalone restaurants in Bikaner, so it’s best to restrict your dining to the hotel you are staying in. Bhanwar Niwas, in particular, has very good vegetarian food, and both Lallgarh Palace and Laxmi Niwas have passable buffets.
If you are not averse to a bit of streetside dining, Station Road has a number of small restaurants where the snack-style samosas and kachoris and ras malai are very good. Try, in particular, Chotu Motu Joshi and Bikaner Bhujia Bhandar.
Bikaner is best known for its savouries, particularly bhujia, various namkeens, papads and baris. Do check out the small shop on Station Road from where the successful food chain Haldiram’s began its phenomenal journey.