Brian O'Shea – a brother of Kevin's wife Catherine – was on holiday in July with his wife Maria and four children in Denmark when the horrific crash happened.
Little Soren (11), Saoirse (9) and Connor (3) tragically lost their lives.
As his cooking empire continues to grow, Kevin has been spending more and more time in the States where his new book and cooking show will be launched.
While he misses being away from home, the Wexford native says the tragedy has hit home just how precious family life is.
"It was an awful tragedy, but you don't really know what is around the corner," Kevin told the Herald.
"You look at your own children and they're so precious, you have to cherish them while you have them."
The chef, who launched his new cooking book Modern Irish Food this week, tries to bring Catherine and children Emily, Sophie and Tom across to America as much as possible.
Modern Irish food also kicks off on RTE 1 this Friday to coincide with the book.
"Catherine is coming over in October and we are going to go for a drive and have a five-day holiday," said Kevin.
"We are going to do the Blue Ridge drive in South Carolina."
Kevin said is brother-in-law and wife were taking life "day by day" since the tragedy and have set up a charity, The Three Musketeers, to help other children.
"Saoirse was profoundly deaf so they want to help deaf children and give them the life they deserve," said Kevin.
His success across the Atlantic is turning him into a household name and sees him travel across to the States every five or six weeks.
"We have a restaurant in Florida so I'm there every six weeks anyway and I have a show out on NBC.
"Modern Irish Food doesn't launch there until October 26 and the book is coming out too so I think it is going to be big.
"I used to love going to America where you can have chill out time, whereas here in Ireland a lot of people would know me when I'm going for a pint.