How write a test case order a single meal??

How to write a test case for order a single meal.
Precondition is
1. Patron is logged into COS.
2. Patron is registered for meal payments by payroll deduction

post condition is :
1. Meal order is stored in COS with a status of “accepted”.
2. Inventory of available food items is updated to reflect items in this order.
3. Remaining delivery capacity for the requested time window is updated to reflect this delivery request

can u advise how to write a test case based on these conditions.

Nice scenario.

Here you need to apply boundary value analysis on available stock and order we can serve.

Security test cases will also required for payment system.

It will better if you post test acses you have written for it and experts do verification here.