To cook right away, combine broth, water, ground black pepper, oregano, basil, onion salt, parsley, garlic powder, bay leaf, and salad dressing mix in a medium saucepan.
Stir well. Heat until the broth mixture just reaches a boil.
Remove from heat.
Place roast in slow cooker.
Pour salad dressing mixture over the meat.
Cover, and cook on low for 8 hours.
At this point, shred meat with two forks.
Return to the crockpot and let cook for 1 additional hour on low.
Notes
To freeze, combine all of the ingredients in a freezer-safe bag or container. Do not cook; simply stir it all together. Freeze for up to three months. Thaw overnight in the fridge. Add to slow cooker, and cook as directed above.