In a pot, add 1 liter of water, 60g salt, garlic cloves, thyme and black peppercorns. Bring this to a boil and let it cool.
Add the brine to a glass bowl with the chicken breasts.
Cover and move this to the refrigerator to marinate for 24-48 hours.
Remove the lid and let the bowl sit at room temperature for an hour. Remove and wash the chicken nicely.
Pat dry and season with your favorite seasonings and a bit of oil. Transfer to a baking sheet lined with parchment paper.
Pop it in the oven preheated at 400 degrees for about 25 minutes, or until the chicken is completely cooked. Let it rest for 10-15 minutes and slice.
Notes
If you really love those perfect thin slices, take your time to slice through the chicken. It gives you more control over the thickness of the meat.
You can also try this with another lean protein like turkey. Just remember that the cooking time will change accordingly.
If you're worried about the high sodium content, reduce the amount of salt you're adding to the brine, or use a low-sodium seasoning to season the chicken before you bake it.