Kante starred for Ranieri's Leicester City last season as the Foxes won the title despite starting the campaign as 5,000/1 outsiders.
The France international's all-action displays in central midfield earned him a £32million move to Chelsea last summer, and the 26-year-old has become a key player for Antonio Conte.
Kante's performances have made him the clear favourite to be crowned PFA Player of the Year as he closes in on a second Premier League title in as many years, though Ranieri - who was sacked by Leicester earlier this season - hailed the Stamford Bridge star after starting life in England on the Leicester wing.
Speaking about signing Kante in summer 2015, Ranieri told Sky Sports: "We were looking at another international player to put there.
"We had lost [Esteban] Cambiasso… I tried to keep him but he wanted to leave. We wanted an international but he didn’t choose Leicester.
Then at the end we had Kante and [Jordy] Clasie. I said, OK, take Kante, I like Kante.
"I watch him two, three times. Kante slowly, slowly started. I put him on the left wing early on because during the training session I thought I had to get him in somewhere.
"How can I not put him in the team? He supported everybody. He and Drinkwater made a very big difference."
Kante has drawn favourable comparisons to Chelsea legend Claude Makelele due to his control of defensive midfield, but Ranieri sees the former as a stronger attacking presence for the Blues.
"He’s no Makelele," he continued. "Makelele’s less mobile, more organised. Kante is about getting the ball and counter-attacking.
"This man is very serious. He’s born for football. If you give him something he’ll make the maximum.
"Always laughing. Never complaining. If he speak behind me I don’t understand him because I’d never recognise his voice."