Place the chicken breasts in a pot and cover them with cold water or broth by about an inch. Season with kosher salt. Feel free to add lemon slices, onions, garlic, or herbs for extra flavor.
Bring the water to a gentle simmer over medium heat. If any white froth forms on the surface, it's just chicken fat, which you can skim off.
Once simmering, cover the pot and reduce the heat to low. Let the chicken cook for 10 to 15 minutes, or until it reaches an internal temperature of 165°F.
Remove the chicken from the pot and let it rest for a few minutes. This is a good time to dice or shred the chicken for meal prep, if needed.
If you want to keep the poaching liquid, strain it through a fine mesh sieve and store it in the fridge or freezer for future use.