To initiate a Royal Commission, you would first need to identify a significant issue that warrants such an inquiry. Royal Commissions are usually established for matters of high public interest or importance, often involving systemic issues or widespread concerns in society.
Gather Evidence: Collect information and evidence to support your claim that the charge for sauce is part of a larger issue, such as pricing practices in the food industry or consumer rights violations.
Engage Stakeholders: Consider rallying support from other customers or consumer advocacy groups who may have experienced similar issues or share your concerns regarding pricing practices.
Contact Your Local MP: Write to your local Member of Parliament (MP) to express your concerns and request their assistance in bringing attention to the issue. MPs are often the first point of contact for issues that may warrant government inquiry.
Prepare a Detailed Case: Clearly articulate why you believe the issue is significant enough to warrant a Royal Commission. This may involve discussing larger market effects, implications for consumer rights, or patterns of unfair practices.
Media Engagement: Local media outlets may be interested in your story, especially if it reflects a broader trend. Public interest can sometimes prompt a government response.
Petition Government: You could start a petition calling for a Royal Commission into food pricing practices, gathering support from the community and emphasizing consumer rights.
Follow-up: Maintain communication with your MP and other stakeholders throughout the process, providing updates on the support you’re gathering and continuing to emphasize the importance of addressing the issue.

While starting a Royal Commission is a complex and often lengthy process, especially for what might seem like a small grievance, framing it within a larger context of consumer rights and industry practices may help in presenting a more compelling case.