Cinagro Kitchen + Market in the basement of the building that houses the MoMa store. It is an organic cafe and market and they offer a great lunch deal. I had a cured ham, parm and avocado sandwich on fresh baked wheat bread and it included a yummy mushroom soup and a trip to their salad bar. Awful music, but that's
to be expected in Tokyo. My lunch plus an iced coffee came out to ¥1,050 - about $12! Not bad!
Cinagro Kitchen + Market
GYRE Building, B1F, 5-10-1 Jinguame
Omotesando Station (Chiyoda, Hanzomon, Ginza) or Meiji-Jingumae Station (Chiyoda, Fukutoshin)