I actually made this a couple of weeks ago so the details are a little fuzzy, but I threw it together on the spot anyway, so it's one of those recipes to be freely modified according to taste.
Begin by dicing an onion and chopping up a mango (1 for 2 tilapia)--set the mango aside.
I began with onion sauted in olive oil, as per the usual, and as it began to turn brown I added about 1 tsp of cinnamon, .5 tsp of cayenne and a little salt as well as a chopped up dried chili pepper (fresh would work equally well). Once that was quite fragrant, I put the tilapia filets in the pan and a little water to keep things from sticking, and once the fish was nearly cooked I threw in the mango. Let the mango get hot and juicy but be careful not to overcook it.
Enjoy with sticky jasmine rice. A side salad would round out the meal nicely.