Pat the chicken completely dry and season generously with salt only. Skip pepper at this stage—it burns during searing and turns bitter.
Heat olive oil in a skillet over medium heat. Place chicken skin-side down (or the fattiest side for drumsticks) and don’t touch it. Let it brown deeply, 8–10 minutes. Flip and cook another 3–4 minutes. Remove chicken to a plate.
Lower the heat. Add butter, shallot, and garlic. Cook until soft. Stir in tomato paste and cook 1–2 minutes until it darkens slightly.
Add soy sauce, Worcestershire, and chicken stock. Scrape the pan thoroughly to release all the browned bits.
Return chicken to the pan. Cover loosely and simmer gently for 20-30 minutes until tender but still intact. Constantly check the simmer because you CAN NOT boil the chicken, that will make it dry and stringy. You must simmer at a lazy bubble. You can also cover and put the entire pan/pot into a 300F oven. Either works.
Remove chicken from the pan. Turn off the heat. Whisk in the cold butter, one cube at a time, until the sauce becomes glossy and velvety.
Spoon sauce over the chicken. Finish with fresh oregano, chopped parsley, and freshly cracked black pepper.
