One of the biggest complaints shared across the ChefVille community of players is the game's overly demanding Salt requirements, and the inability for players to earn enough Salt each day to keep up with those demands. To help alleviate the pain, Zynga has started the slow rollout process for a new "Salt Crystal." This item must be built, as funny as that sounds, and you'll be able to use it to harvest Salt from right within your restaurant, but only for a limited time.
This Salt Crystal is available for 200 coins in the game's store, and it requires just one energy to unwrap. From there, you'll need to ask two friends to come work as staff inside the item to actually finish it off. After you've completed the Salt Crystal, you'll be able to harvest five Salt from it, once every 30 seconds. When those five harvests are gone, so is the Crystal, and you'll need to start from scratch on building a new one.
Unfortunately, this means that you're spending 200 coins (plus a lot of time waiting) to earn five Salt units, but I suppose a method to earn some free Salt is better than no method at all. I wouldn't be surprised if a new "Pepper Crystal," or another similar item is released in the game as well in the near future, and if that's the case, we'll make sure to let you know.