Place chicken breasts between two sheets of parchment paper. Using a meat mallet, gently pound to an even thickness of approximately ¾ inch.
Optional but recommended: Dissolve kosher salt in cold water. Add bay leaf and thyme. Submerge chicken completely and refrigerate for 60-90 minutes.
If brined, thoroughly rinse chicken under cold water to remove excess salt. Pat completely dry with paper towels.
Combine garlic, coconut aminos, lemon juice, salt, pepper, and dried herbs in a bowl. Coat chicken breasts thoroughly, ensuring complete coverage. Allow to marinate at room temperature for 20-30 minutes maximum.
Heat cast iron skillet over medium-high heat. Add avocado oil and heat until shimmering but not smoking (approximately 375°F).
Place chicken presentation-side down in the skillet. Cook undisturbed for 5-7 minutes until golden brown crust forms.
Flip chicken breasts once. Reduce heat to medium. Continue cooking for 5-7 minutes or until internal temperature reaches 160°F at thickest point.
Transfer to a clean cutting board. Tent loosely with foil. Rest 5-7 minutes to allow carryover cooking to reach safe 165°F while redistributing internal moisture.
For optimal texture, slice perpendicular to muscle fibers at a slight angle.