We used garlic fire-roasted tomatoes because they didn't have plain ones, so that works.
Also, if you want to ladle it over a bed of rice or something like that, which I did (instead of putting it into a tortilla like my_partner_doug did), then you don't necessarily have to shred the chicken. I just bailed out a thigh and added the other bits around it.
Next time, I want to use mango puree instead of mango nectar, and add a can of tomato paste, to thicken the liquid more.
If you don't want to butcher a live, struggling mango for this recipe then I suspect that frozen, thawed chunks would work just fine.
EDIT 9/16/20 -- Tonight we reheated leftovers to serve over boiled eggs, and that was delicious too. :D