Programmatic creation of flex objects

I’m looking to save some data in the user/data folder as part of a plugin’s functionality and I’d like to use the flex object interface for its promise of advanced CRUD operations. However, I’m not sure how to create and store a flex object programmatically.

On a simple checkout form I define a custom action, which I can hook into on onFormProcessed, that part is fine. Now I’d like to create an order object and save it in the data folder. How do I go about this? Let’s say for now the order object contains the order date, a product id and a price.