Bizznessman gave you the best advice. There are a lot of issues with partnerships and the one that looms large is that you assume his half of all liabilities in your partnership. Will this be a separate business from his gas station? Will you have other responsibilities other than cooking? Do you trust him?
One of the rules I use, is would I marry this person? If the answer is no, then skip the partnership and work out a different deal. Even leasing the space and cooker, running the business as your own, and splitting profits, if there are any, is preferable.
The SS Platypus, sails again, to the support of the Vets!
"perhaps...but then again...maybe not..."