Mix salt, sugar, peppercorns, thyme, rosemary, garlic, onion, bay leaves in pot with water. Stir until dissolved.
Submerge the pork butt in the brine. Add more water if needed to cover it completely.
Remove pork from brine, discard liquid, and rinse under cold water to remove excess salt.
At this point, you can proceed with your preferred cooking method, such as roasting or smoking the pork butt.