1. Stab your tenderloin along top edge every 1-2 inches. Stuff a slice of garlic in each slit created. Then place your tenderloin in a 6-quart slow cooker.
2. Sprinkle soup mix over tenderloin, the pour over water, broth, vinegar and soy sauce. Sprinkle pepper on top.
3. Cover and cook on low for 4 hours.
4. When done cooking, remove loin from slow cooker and let rest for 10 minutes before slicing.
Serve with au jus drizzled on top.