I don't get the last part of your question ("Angels with Scaly Wings"), is that a reference to an eponymous visual novel? (that I've just discovered and will keep in my bookmarks)

Dragons aren't all equipped to breathe fire.
Some do, some don't, some shapeshift to get fire breath when needed.
I'm in the last category.

Now, in a modern world like ours, that would be a hell of a dangerous way to cook!
Wouldn't recommend, as you would most likely burn yourself, someone or something else, or appliances.

In a more fantastic setting, I suppose it'd be used to cook stuff "a la plancha" or to light a fireplace, not directly aimed at food.

... however, nothing (in my universe) forbids you from cooking food using your fire breath, but there are few reasons why you'd do that...