The 24-year-old defender moved to St James' Park from Palermo in the final days of the summer transfer window for a fee of around £3m.
The Moroccan is highly thought of in Italy and had the opportunity to play Europa League football when Fiorentina came calling.
But the defender says it has always been his dream to play in England and he was delighted when Newcastle made a move despite their Championship status.
"I had to choose between Newcastle and Fiorentina," Lazaar told TMW.
"Fiorentina are a great club, but my head and my family told me, 'go to Newcastle'.