"I was hired on as a sous chef and my executive chef has since quit, and the owners have since asked me to fill in a run the kitchen"
Corporate asked you to fill in and did not promote you. They may be saving money by not replacing the exec chef until closer to opening. Then they will hire someone with more experience. Don't let your ego and inexperience set you up for a fall. Here is an example of a job description for a corporate exec chef, do you and your duties fit the example?
Responsibilities: The executive chef will train and manage kitchen personnel and supervise/coordinate all related culinary activities; estimate food consumption and requisition or purchase food; select and develop recipes; standardize production recipes to ensure consistent quality; establish presentation technique and quality standards; plan and price menus; ensure proper equipment operation/maintenance; and ensure proper safety and sanitation in kitchen. The executive chef may cook selected items or for select occasions. The executive chef may oversee special catering events and may also offer culinary instruction and/or demonstrate culinary techniques. The executive chef directly supervises kitchen personnel with responsibility for hiring, discipline, performance reviews and initiating pay increases. Typically reports to a food service director.
Special qualifications: The ability to manage in a diverse environment with focus on client and customer services is essential to success in this role.
Experience: Previous experience with control food and labor cost, demonstration cooking, menu development, and pricing and development of culinary team preferred. Premise and liability accountability and contract-managed service experience is desirable.
Education: The ideal candidates will possess a bachelor's degree or related culinary degree with eight or more years of industry and culinary management experience.
Core competencies: Leadership, Management, Planning