Preheat your sous vide precision cooker to 145°F (63°C).
Season the chicken breasts evenly with salt, black pepper, garlic powder, onion powder, and thyme (if using).
Place the seasoned chicken breasts inside a zip-lock or vacuum-sealable bag. Add the olive oil to the bag.
If using a zip-lock bag, use the water displacement method to remove the air: seal the bag almost all the way, submerge it in water until the air is pushed out, then seal completely.
Place the bag in the preheated water bath, ensuring it is fully submerged. Cook the chicken for 1 hour.
After cooking, carefully remove the bag from the water bath. Take the chicken out of the bag and pat it dry with paper towels.
Heat a skillet or grill over medium-high heat. Sear the chicken breasts for 1-2 minutes on each side until golden brown.
Let the chicken rest for a few minutes before slicing.
Serve the chicken garnished with fresh herbs or lemon slices if desired.