the worldmap node has an example of this in its examples... the simple trick is to use a "normal" template node to create the html to feed a ui-template node on the dashboard - BUT you need to add the angular filter | trusted so that it doesn't strip out any extra tags that it would otherwise try to remove.
[{"id":"1271593d.5d1a27","type":"inject","z":"dfe4ec36.0a5a5","name":"","topic":"","payload":"","payloadType":"str","repeat":"","crontab":"","once":true,"onceDelay":"","x":310,"y":1200,"wires":[["33bad88.3a3b028"]]},{"id":"5778320b.bba91c","type":"ui_template","z":"dfe4ec36.0a5a5","group":"53e6c4b8.1b0f7c","name":"","order":0,"width":"6","height":"6","format":"<div ng-bind-html=\"msg.payload | trusted\"></div>","storeOutMessages":true,"fwdInMessages":true,"templateScope":"local","x":680,"y":1200,"wires":[[]]},{"id":"33bad88.3a3b028","type":"template","z":"dfe4ec36.0a5a5","name":"","field":"payload","fieldType":"msg","format":"handlebars","syntax":"mustache","template":"<iframe src=\"/worldmap\" height=300px ></iframe>","x":510,"y":1200,"wires":[["5778320b.bba91c"]]},{"id":"53e6c4b8.1b0f7c","type":"ui_group","z":"dfe4ec36.0a5a5","name":"Default","tab":"d78b32f4.2797f","disp":true,"width":"6"},{"id":"d78b32f4.2797f","type":"ui_tab","z":"dfe4ec36.0a5a5","name":"Home","icon":"dashboard"}]
