How to contract the hotel kitchen to the chef? Specific, how to do the details?

1 small contract: you pay everything you need in the back cabinet and sign a contract with the chef, subject to the customer's consumption bill! What percentage of the total cost is paid to him every month? 2. big contract: he will pay for everything needed in the back cabinet! Subject to the customer's consumption bill! What percentage of the total bill does he pay every month? 1.2. The kitchen management is his!