English lesson: in a restaurant

We use the determiner 'the'

when requesting specific food in a restaurant. Example:

Can I have the chocolate cake please?

I would like the cottage pie please?

The beef casserole, please.

We use the determiner 'a' when requesting general, non-specific items. Example:

Can I have a glass of wine please?

Can I have a bowl of ramen please?

A pint of beer, please.

Of course, if you are ordering more than one item he number replaces the determiner.

Does that make sense?