Maybe 5 stars is a bit of a exaggeration because it's not like their food is perfect, for instance the naan isn't particularly good but overall their food is great. Fast, affordable, a block from my office and with enough spice to actually taste interesting.
The spice thing is a big peccadillo of mine because most of these lunch spots really turn down not just the heat but overall flavor to suit the typical business lunch crowd. Nirvana II don't compromise as nearly as much and their food is adequately flavorful.
The menu also rotates regularly so you never get too bored of what's available. Still i mostly go there on Fridays when they have their fish curry which i'm rather partial to.