Pat the chicken dry with a paper towel and set aside. Add the lemon pepper seasoning, garlic powder, smoked paprika, onion powder, dried thyme, kosher salt, and avocado or olive oil to the bottom of a medium bowl. Mix together to form a paste, then add in the chicken thighs, tossing until they're evenly coated in the seasoning mixture. Marinate covered in the fridge for at least 30 minutes or up to 2 hours.
Preheat the oven to 375ºF/190ºC. Heat a large oven-safe skillet over medium-high heat with one tablespoon of oil. Once hot, add the chicken thighs and sear for 3 minutes with the skin side down. Flip the chicken over and sear for another 2 minutes with the skin side up. Transfer to the preheated oven and cook for 30 minutes.
While the chicken is cooking, make the sauce. In a saucepan over medium-low heat, melt the butter and add the minced garlic, honey, and soy sauce or tamari. Once combined, add in the fresh lemon slices. Simmer for about 5 minutes or until the sauce starts to thicken.
Spoon the sauce over the thighs, add the lemon slices to the pan, and put it back in the oven to caramelize for another 5 minutes or until it reaches an internal temperature of 165℉/74℃. Spoon the sauce from the pan over the chicken again before serving.