In Hungary it's customary to eat breakfast within the warmth of the family home. However, this tradition has been eroded by increasing number of foreigners and tourists. These days in Budapest you can find several options for a croque-monsieur to start your day. Here is a list of casual, no-frills cafés with outstanding breakfast. If you're looking for a trendier venue, try one of these.
Prix fixe lunches are available in many restaurants (on weekdays) at a reasonable price, usually ranging between €5-7. Before choosing à la carte, it's worth inquiring about a set meal.
Free water and free refills are unknown concepts in Budapest (and in greater Hungary). In restaurants you should specifically ask your server for tap water (to which the likely reaction is annoyance), otherwise they will serve you and charge for bottled water.
Please mentally prepare yourself for potentially disappointing customer service in Budapest. Waitstaff with an attitude is a general Eastern European phenomenon and, while things have somewhat improved, Hungary is a severe case.
As for tipping, 10% is the standard and expected in Hungarian restaurants and bars, with up to 20% for exceptional service. Please note that lately some places have begun to add an automatic service charge (in the range of 10-15%) to the bill.
A word to the wise: as many cafés, restaurants, and bars are cash-only establishments, it’s generally a good idea to carry money with you.