Put the chicken in a pot with the spices and enough water to cover. Put a lid on it and bring to boil over high heat. Turn off the heat and let chicken steep for 10-15 minutes.
Drain and cool.
Stab sweet potato with a fork several times and microwave 3-6 minutes until soft. Cook.
Shred chicken and mix with minced green onion and mashed, peeled sweet potato. Taste for salt and add a little more now if it needs it.
Roll 2 tablespoons of mixture in corn tortillas and fry in shallow oil until crisp and brown.