Mix up the taco seasoning and set aside.
If not already skinless, remove the skin and any excess fat from the thighs. Sprinkle about half the seasoning on the thighs.
Cover the bottom of a large dutch oven with a little olive oil and brown the thighs on both sides.
Add the tomato sauce and turn the thighs over to coat. The sauce doesn't have to completely cover the thighs. You can add a little more sauce (or water or broth) if needed while the thighs are cooking.
Reduce the heat to medium low and cover the dutch oven.
It will take about an hour to cook the thighs. Turn the heat off under the dutch oven and remove the thighs to a platter or bowl to cool.
When cool enough to handle, remove the meat from the thighs and pull into shreds. (I use my hands for this).
Eyeball the remaining sauce and if you feel like it's too much for the meat, take some out.
Return the shredded meat to the sauce and season as desired with the remaining taco seasoning. Add more sauce if needed.
Use any leftover sauce to moisten the pulled chicken taco meat before storing in the fridge.
