Princess Diana was ahead of the trends when it came to her go-to breakfast, according to her former royal chef.

Darren McGrady revealed the exact recipe for the breakfast that the late Diana ate "every day," which she requested be incorporated into her frequent meal rotation.

"When I became Princess Diana's chef, she got her life back on track. She was a patron of 119 different charities, she was working out at the gym three days a week and just looking the best she ever did," McGrady explained in a YouTube tutorial posted on June 27 that was titled, "Princess Diana's Overnight Oats."

"She said, 'Darren, you take care of all the fats, and I'll take care of the carbs at the gym.' Now this meant she was now eating healthy, and her go-to breakfast was something called overnight oats," he shared.

While overnight oats became popular around 2012, Diana was enjoying the meal nearly 20 years before in 1993.

"She actually went to a Swiss health clinic, and there she had these overnight oats. They were actually called bircher muesli, and they were invented by a Swiss nutritionist," McGrady said. "She thought they were really, really good and all the ingredients were super healthy. She stole the recipe, came back and said, 'Darren, I want these for breakfast every day.'"

In addition to revealing Diana's favorite breakfast, McGrady also shared a tutorial on how to make the dish just like the former royal liked it.