This takes some time, but isn't hard at all. And even though it takes time, YOU don't spend a lot of time on it. The only skill you really need is in deboning the chicken thighs. You can make this up ahead--After it comes out of the oven leave the chicken oil until it cools considerably. You can store it in the fridge for up to 2 days before finishing it. You may need to rewarm the pan in a low oven to return the fat/shortening to a liquid state.
Debone 4 chicken thighs. Sprinkle them with kosher salt, freshly ground pepper, crushed garlic and place a sprig of fresh thyme on each one.
You can cover the chicken with plastic wrap and refrigerator overnight but if you have a food saver, place the chicken in a bag and suck away.
The next day, preheat the oven to 220 degrees Fahrenheit. Line a pan with parchment paper....
pat the chicken dry with paper towels and remove the thyme. Place the chicken in the pan....
Cover the chicken with 3 parts vegetable shortening and 1 part lard. Okay, you can use nothing but vegetable shortening if you want, or even olive oil. It will look pretty nasty.
Place the pan in the oven. Check it half an hour later to make sure the chicken is completely submerged. If needed, add more oil.
Let it cook for 4 hours...then take it out and make sure the temp is around 210 degrees.
the chicken is so tender it can easily fall apart. Very carefully remove it from the pan and allow it to drain on a wire rack.
Preheat your oven to 450 or a convection oven to 400. I have a Segura Turbo Convection oven on the counter and used that. When it's preheated, put the chicken in.
in 5 minutes you'll notice it browning nicely.