It turns out that a steaming bowl of noodles may be an antidote to the city’s real estate woes. While ramen noodle restaurants — modeled after traditional noodle bars in Japan — have been in the city for ages, new noodle shops are popping up with increasing frequency, and they not only offer inexpensive meals for bargain-hungry diners but also a source of deals for brokers with retail leases to spare.