Since pocketing a prize package valued at over $100,000, McGregor has moved from Christchurch to Auckland where he has been busy establishing an impressive list of contacts in the food industry. He's popped up on our televisions suggesting we fill our supermarket trolleys with broccoli; published a book (and just completed a second); guided foodies on overseas jaunts; headed pop-up restaurants; and become an ambassador for a kumara grower and a whiteware distributor.
"I'm doing what I love and when you are doing that it doesn't feel like you are working, so everything has changed. If you really enjoy what you are doing you are pretty motivated to make sure that it continues. I love what I am doing and I just couldn't imagine going back to a classroom."
Season two winner Nadia Lim has been just as busy establishing herself as a food industry identity. Her recently launched business, My Food Bag, is a joint venture with former Telecom chief executive Theresa Gattung, childcare entrepreneurs Cecilia and James Robinson and Nosh general manager Mike Wales.
Lim, who is the public face of the company and designs the menus, estimates she is putting in "over 100 hours a week easy" into the business, which launched 11 weeks ago.
"I was a bit nervous about how Kiwis would take being given their menu for what meals they are going to have for that week. They get all of the recipes created for them and the ingredients delivered to their door, and it's always a surprise. But people just love it."
Since winning MasterChef about two-and-a-half years ago her feet have hardly touched the ground.
"Very full on - a whirlwind - but I can't complain," is how she describes it. "I'm super, super busy. I have to work five times harder than I did in my old job [as a clinical diabetes dietitian]. I sometimes miss my old nine-to-five job. But I can't believe I get to do what I dreamed of when I was a 12-year-old kid."
Like McGregor, winning MasterChef has been a life-changing experience for Lim.
"I still feel exactly the same but my day job is very different."
As well as My Food Bag, Lim works as a food writer, consults to food companies and has just signed a deal for a second book after her first, Nadia's Kitchen, sold enough copies to require three print runs.
McGregor didn't know the exact sales figure for his first book, Taste of a Traveller - New Zealand's first MasterChef, but reckoned it sold "10,000 copies easy".
A spokeswoman for publisher Random House would not reveal book sales figures for the MasterChef winners but said "they all sold very strongly".
McGregor, who still drives the Toyota Prius he received in his prize package, spends plenty of time in the kitchen, although his view of his cooking skills has been hit by a reality check.
"I'm cooking all the time but I think it has got worse," he laughs. "You win the show and you get these delusions of grandeur about how fantastic you must be, and then you come out into the real world and realise just how much there is to know."
Season three winner Chelsea Winter could not be reached for this story, but she has published first book At My Table and is an ambassador for New Zealand Beef & Lamb and Kim Crawford Wines.
What previous winners have done
Brett McGregor - Season one
• Television commercials.
• Food and Wine ambassador for Mondo Travel, hosting culinary tours overseas.
• Published first book Taste of a Traveller - New Zealand's first MasterChef. Has deal for second book.
• Brand ambassador for Kaipara Kumara.
• Ambassador for Blue September.
• Runs Parmco Let's Cook programmes.
• Charitable work for Heart Foundation.
• Headed pop-up restaurants, including The Tasting Lounge at Wynyard Quarter.
Nadia Lim - Season two
• Television commercials.
• Started new business My Food Bag.
• Published first book Nadia's Kitchen.
• Worked at Euro restaurant.
• Food writer for various magazines, including Herald's bite mag.
• Food consulting.
• Signed deal for second book.
Chelsea Winter - Season three
• Published first book At My Table.
• Has website Chelsea Winter, Simply Good Food.
• Ambassador for NZ Beef & Lamb and Kim Crawford Wines.
Prize packages
• Chelsea Winter: Last year Chelsea won $20,000 in groceries from Countdown, a Skoda Superb car, Izona appliances from Fisher & Paykel, kitchenware from Stevens and a cookbook deal with Random House.
• Nadia Lim: Nadia won $20,000 in groceries from Countdown, a Skoda Octavia car, Izona appliances from Fisher & Paykel, kitchenware from Stevens and a cookbook deal with Random House.
• Brett McGregor: Brett won a Toyota Prius i-tech car, Fisher and Paykel Izona appliances, kitchenware from Stevens and a cookbook deal with Random House.
MasterChef final
Aaron vs Paula, Sunday 7.30pm, TV1