2 adjectives to describe sangfroid

Accordingly, when the supper was nearly over, he held up the glove and asked with a loud voice if any lady had lost a glove; when his own wife who was sitting at the same table at some distance from him called out with the utmost sangfroid: E il mio! dammelo: l'ho lasciato cadere.

It is altogether magnificent in its sheer sangfroid.

2 adjectives to describe  sangfroid