Most taquerias in the Boston area are counter service, fast food-type places. You order your burrito and move down the line, making sure you get all the right fillings. But at Taqueria Mexico, in Lynn, Waltham, and Coolidge Corner, Brookline, a hot, cheap, delicious, and sit-down meal is only a few minutes away. The Brookline location is small, with only a handful of tables, so service is quick. Hot and fresh tortilla chips and......