Kate Middleton’s Brother, James Middleton, on His Sweet New Company, 'Boomf'

— -- What does it mean to be uncle to the future King of England?

For James Middleton, the uncle of Britain’s Prince George, it means, just like in any family, trying to be the best uncle you can be.

“I still see Prince George as my nephew and I just want to be the best uncle possible,” Middleton told ABC News’ Amy Robach in an interview that aired today on “Good Morning America.”

“Like any uncle wants to be, I want to be the cool uncle. The fun uncle,” he said. “That’s what sort of I’ll always try and be.”

Middleton, the brother of Prince George’s mom, Duchess Kate, is making his own splash with the launch of his personalized marshmallow company, "Boomf."

The company, for which Middleton holds the cheeky title “Wonka-in-Chief,” is one he created with his business partner, Andy Bell, who holds the title “Chief Edible Officer.”

“We thought we'd just add the fun throughout the company so the staff in production are 'Boomfaloopas,'" Middleton said. "We obviously take a lot of sort of magic from Willy Wonka."

Marshmallows from 'Boomf' may be a perfect Christmas gift, but Middleton, who resides in the U.K., says he "hasn’t even gotten that far yet” when it comes to finding a gift for Prince George.

When it comes to finding gifts for his family, Middleton scored big when he gave Kate and her husband, Prince William, a dog they named Lupo for their wedding. The dog is often seen out with the couple and has been included in at least one of their family photos released to the public.

“It was my sort of little treat for them was to give them a puppy,” Middleton said. “And Lupo was their gift.”

The Middleton family – which also includes a sister, Pippa Middleton – is expecting a new little bundle of joy this spring when Kate is due to give birth to her second child. The child, whose gender is not yet publicly known, will be fourth-in-line to the British throne.

Middleton says his sister is “on the mend” after suffering from hyperemesis gravidarum, a condition characterized by acute morning sickness, early in her pregnancy.

“She’s better,” Middleton said. “I mean it’s not unknown that she suffered from this acute morning sickness and fortunately she is, I think, on the mend.”

Middleton says his family sees and talks to each other “all the time” and even though the world’s eyes are focused on William and Kate, major events like their wedding and the birth of Prince George seem like just family affairs.

“The most wonderful thing about that wedding,” Middleton said, referring to William and Kate’s 2011 nuptials, “although billions were watching, it felt like a family wedding.”

And as for Prince George’s August 2013 birth, at which hordes of media camped outside the hospital, Middleton says it was again about the family.

“I think what was the most wonderful thing, everybody was celebrating with us, for me becoming an uncle and for my parents becoming grandparents, they’re all so excited,” Middleton said.