Mince garlic very finely, or mash to a paste with the tines of a fork, or grate on a microplane. You want it to be reduced to very small bits.

Strip any stems from all of the herbs, and chop them well - they should equal about a half cup total when they are all chopped.

Using a non-reactive container [stainless steel or glass], whisk together the olive oil, vinegar, egg, salt and pepper. The egg is to keep the mixture emulsified, and though it is often left out of the original recipe. I think it works better with it.

Whisk in the chopped herbs and garlic.

Trim the excess skin and fat from the chicken thighs - not all of it, just anything that might hang down on the grill and get burned anyway.

Wash thighs, and pat dry with paper towels.

You can just put the chicken in the bowl with the marinade, but I like to put it all in a large ziplock bag. Make sure all of the air is pushed out and it is well sealed. For extra insurance I lay the bag flat on a large plate or in some other flat vessel. A couple times a day, I just flip the bag over and kind of mush everything around a little to make sure all the thighs are getting marinated.

After 24 - 48 hours, take the chicken out of the fridge. Arrange the thighs in a large saute pan or dutch oven - it is best if they can all lay flat, but if you don't have a big enough pan for that, get it as close as you can.

Pour over the marinating liquid, and set the burner at medium. Watch carefully, and when it starts to boil, turn it down to barely simmering. After 10 minutes, turn each piece carefully, and cook another 10 minutes. Remove from the heat.

Get your grill heated up, and be sure to oil the grates.

Once the grill is well heated, place the chicken, skin side down, on the grates. Keep the heat at about medium. You may have some flare up because the oil is going to drip down some, but a spray bottle of water kept handy will take care of those.

Don't turn the chicken until you can pick it up off the gates without tearing the skin - when it is ready to turn, it will come up easily. This will take around 8 to 10 minutes, depending on your grill. Brush the marinade over the upper side a couple times during cooking.

Turn and grill the second side for another 5 to 8 minutes. If you want to be sure it is cooked through, check the internal temperature, which should be about 165º [74ºC]

Let it rest around 5 minutes, and then serve hot. Leftovers should be refrigerated and are great cold.