The Caribbean Journal has a great article about San Ignacio, and they talk a lot about pupusas. They also mention many of the sights and local restaurants. Worth a quick read.
"San Ignacio is increasingly finding itself on the radar of travelers, with its blend of authentic Belizean culture and unique position as a jumping-off point for some of the most exciting adventures in Belize’s hills, rainforests and rivers.
Whether you’re making the journey to the see Belize’s towering Maya site called Caracol, exploring cliffside pools or waterfalls or journeying to the seemingly endless, winding rivers, San Ignacio is the perfect headquarters for your vacation."