Apex domains cannot have CNAME records.
Question and response
Question
dig gastronomie-provencale.com. NS
Answer
gastronomie-provencale.com. 5 NS ns-2038.awsdns-62.co.uk.
gastronomie-provencale.com. 5 NS ns-1537.awsdns-00.co.uk.
gastronomie-provencale.com. 5 NS ns-730.awsdns-27.net.
gastronomie-provencale.com. 5 NS ns-1439.awsdns-51.org.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0