Rendang originates from Indonesia and is popular among several countries and Southeast Asia. It's a type of heavily-spiced curried meat dish that's been reduced so that there's not much liquid remaining.
Chicken Rendang Deluxe comes with both a chicken and potato rendang featuring the flavors of coconut, lemongrass, and chili. On the side you'll find coconut rice, sliced cucumbers, and crispy padadums, which are crispy, thin-discs of dough that have been fried or cooked with dry heat.
Since rendang isn't a dish you can prepare to order, it's something that would have to be kept in a warmer of some sort, much like Wendy's Chili. Still, it seems like a pretty interesting play for Wendy's to offer something that might not even be considered fast food on the menu.