Sprinkle short ribs with pepper and 1 teaspoon of the salt. Heat canola oil in a large (12-inch) cast-iron skillet over medium-high. Add ribs, and cook until well browned, about 10 minutes, turning once. Transfer to a 6-quart slow cooker.

Add onions, garlic, ginger, and 1/2 teaspoon of the salt to skillet, and cook over medium-high, stirring often, until onions are very tender, 8 to 10 minutes. Add 3/4 cup of the whiskey, and cook 1 minute. Stir in tea and broth, and bring to a simmer, about 3 minutes. Pour onion mixture over ribs in slow cooker. Cover and cook on LOW until meat is very tender and falling off the bone, about 7 hours.

Remove ribs, and set aside. Pour mixture from slow cooker through a fine wire-mesh strainer into a medium saucepan; discard solids. Cook liquid in pan over medium-high until reduced by half (about 1 1/2 cups), 10 to 12 minutes. Add sherry vinegar, 1/2 teaspoon of the salt, and remaining 1 tablespoon whiskey. Stir together cornstarch and warm water; stir into mixture in pan, and bring to a simmer, 2 to 3 minutes. Remove from heat.

Combine parsley, scallions, lemon zest, lemon juice, olive oil, and remaining 1/4 teaspoon salt in a small bowl. Serve ribs in whiskey sauce topped with parsley mixture.