For months — possibly by now it’s for years — I’ve been eating lunch for $3.10 a day by sticking to a bean and rice quesadilla at Anna’s Taqueria. For this you can add salsa, hot sauce, lettuce and jalapenos, but not such things as sour cream or guacamole.

Forced to eat sometimes in Boston rather than Cambridge, I’ve discovered a $3-a-day meal at Ding Ho Fast Food, where Harrison meets Kneeland in Chinatown. This gets you three kinds of food, generously ladled into a styrofoam container. There’s almost always a vegetable or vegetarian option as well as the usual carnivore’s fare, in addition to the basic fried rice, lo mein and rice noodle sides.

Ding Ho is the ultimate in fast food. The food’s waiting behind a sneeze guard, not prepared for each order. You walk in one side and leave on the other. And keep it moving. It’s almost Soup Nazi-ish, although I’ve never seen anyone banished for asking impertinent questions or failing to queue up properly. Ding Ho is also surprisingly under the radar for such a cheap and obvious lunch choice; a variety of Google searches fails to elicit much coverage of this not-so-hidden gem.

My point, I guess, is that if anyone has a lunch option that costs $2.90, I’m keen to hear of it. If I can keep whittling away, a dime per step, I could soon be eating for free.

(I could go down to two dishes at Ding Ho for $2, but it seems like cheating.)