Tammy sings the praises of Comella's, which serves "messes" (big heapin' helpin's of pasta, sauce and some meat or veggie stuff) in West Roxbury, West Newton and Wellesley:

... The dish that we have had twice is called The Paisan's Mess ($10.99/$32.99/$43.99 for the various sizes). It is a combination of "the base", extra shells, extra eggplant (which is breaded and fried) and extra lasagna. One bite and you can't stop shoveling this amazing slop down your throat. While the prices might seem a bit intimidating, these portions are LARGE and WELL WORTH the cost. ...

Ed. mess note: Having tried the West Roxbury outlet, I can confirm that their portions are huge. Bring an appetite (you can eat in, but the dining room is a bit spare; it's really more of a take-out place).