Gronowski was born in Brussels, and survived the Holocaust by escaping deportation in the attack on the twentieth convoy, on 19 April 1943, which would have taken him to Auschwitz.

Gronowski holds a Doctor of Law degree from the Free University of Brussels.

In 2014, Gronowski met British composer Howard Moody at a performance of his opera Sinbad at La Monnaie Opera House in Brussels; Gronowski told the composer the story of his escape and life and ended with the phrase "ma vie n'est que miracles" (my life is nothing but miracles).

The opera was premiered in Bexhill, England, at the De La Warr Pavilion after being commissioned by the Battle Festival.

After an invitation from the House of Commons, PUSH was performed on 27 January 2018 to mark Holocaust Memorial Day, where Gronowski was a special guest.