This can be easier than the average Weekend Warrior wanting to go pro. You can save a lot of cost on permits and licensing if your buddy ties what you do into his business. You are basically a Contractor using the restaurant as an inspected commissary kitchen. Buy thru the restaurant distributor. Prep work in his inspected kitchen. You cook, he sells. You get paid for your time on site and that is up to you and your friend to negotiate how much. A lot depends on the market. Is the place a Family Restaurant with the Blue Plate Special at $8 or a Steak House at $25-30 a plate. What does he pay his Line Cooks? $9-$12-$15 an hour? You are a specialist with special equipment and talent. $15 to $20 an hour would not be out of line with all the meat, rub, sauces, and assorted ingredients paid for and stored by him. He sells at what the market will bear and that's it.
Now if he just expects you to deliver a finished product...That a whole new ball game. You have to cover permits,business license, pay taxes, have an inspected kitchen, carry all the Insurance, go through Food Safety Training and Certification. You do all the Buying, pay distributors, maintain and inventory and storage.Your local laws may require all equipment be restaurant quality and NSF Certified.You can't have what you sell in your home kitchen refer and use the Kmart Crock Pot. You maintain and store the product and prep inventory. Basically you are going through a Catering Business start up and all that entails. Going this route you charge 2-3X the cost of Meat and all ingredients. BUT...That still has to be negotiated because your buddy has to put profit on top of that. If his 16oz Steak is selling at $25 he can't move a Pulled Pork sandwich at $20. This is just a brief overview but should get you started talking further with your friend...JJ