I haven't tried any of these but recipes at allrecipes.com are rated:

http://pasta.allrecipes.com/AZ/BlackBeanLasagna.asp

http://mexicanfood.about.com/library/weekly/aa070401a.htm

http://www.eastcentralenergy.com/about/Recipes/march01.html

http://robbiehaf.com/Recipes/B/191.htm

These are just a few I found using a google search for 'black bean lasagna'. If the recipe you are looking for uses any specific ingredients please let me know and I can try to help further.

AmyT