牛肉面 literally translates to Beef Noodles in English.
Beef noodle soup is a Chinese and Taiwanese noodle soup made of stewed or red braised beef, beef broth, vegetables and Chinese noodles. It exists in various forms throughout East Asia and Southeast Asia. Stewed beef noodle soup was first created by the Hui people (a Chinese Muslim ethnic group) during the Tang Dynasty of China. The red braised beef noodle soup was invented by the veterans in Kaoshiung, Taiwan who fled from mainland China during the Chinese civil war. – Wikipedia.
In Singapore, Hainanese Beef Noodles comes in two forms, soup or dry. The soup version is clear delicate broth as seen in the photos (background – most stalls’ clear soup version are much lighter in colour like Viet Pho) and the dry version actually comes slathered in thick starchy beef stock gravy. The standard type of noodles used in Beef Noodle is actually made of rice flour without using eggs (spaghetti shaped as seen, which we locals called thick/coarse beehoon or the flat shaped kway teow with the former being more popular).

Singapore’s Hainanese Beef Noodles in soup form should taste refreshing yet intense. The colour of the soup can be dark or light and very much akin to the Vietnamese Pho Bo without the herbs. When dining with friends, I would order a variety like Mixed Beef Soup which may contain (depending on which vendor you patronise) slices of beef shin, beef tendon, beef stomach (tripes), beef brisket, beef tongue (ox tongue?) and beef balls. The clear broth is believed to have been simmered for at least 5 to 6 hours with some vendors adding fortifying and nutritious Chinese herbs to it.

The beef noodles I had here was at Kovan Hub, a Kopitiam (local coffee shop) Ri Yi Beef Noodles at *Blk 210 Hougang Street 21, Singapore 530210. I had it upsized and paid S$5 for it. The noodles were done well without being too al dente or soft, just slippery smooth. The beef gravy was not overly starchy nor the clear broth too cloying. It was a decent meal and although this stall may not be the best (so far searches for best beef noodles came out with those recommended below), I do not mind eating here again except next time round, I’ll order mixed beef ingredients.
UPDATE (2018): Mr. William Lee has kindly informed me (in comments below) that Ri Yi Beef Noodles is now relocated to 965 Upper Serangoon Road (MEE SEK FOOD COURT) behind Ponggol Nasi Lemak 椰飯 > 25 meter away from KOVAN MRT Station.
Below are some recommendation on where to eat Beef Noodles in Singapore. They are in no particular rating order as I believe taste is a personal and subjective matter.
Hock Lam Street Beef Kway Teow
22 China St, #01-01 Far East Square
Opening hours: Mon-Fri: 9.30am-8pm; Sat, Sun & PH:10.30am-5pm
Price: From $5.50
Toa Payoh Hwa Heng Beef Noodles
Yeap Coffee Shop
27 Maude Road
Opening hours: Tues-Sun: 11am-3pm; closed on Mon
Price: From $3
Bugis (Long House) Lim Kee Beef Noodle
Golden Mile Food Centre #B1-27
Opening hours: Daily: 11am-9pm
Price: From $3
Beef Kway Teow
#01-19 Changi Village Hawker Centre
Opening hours: Daily:11am-9pm
Price: From $3
Kheng Fatt Beef Noodles
Golden Mile Food Centre #01-89
Opening hours: Mon-Sun: 11am-8pm; closed on Wed
Price: From $3
Happy food hunting