Essien was brought in from Lyon in 2005, there for the peak Mourinho years at Chelsea, when the Portuguese seemed unable to do wrong. Their dynamic was so strong that Mourinho took him to Real Madrid on loan when everything was falling apart around him.
Beyond that, the pair still have an excellent relationship. Essien brought Mourinho to Accra, in Ghana, a few years ago, to show him where he grew up. Mourinho has even taken to calling himself Essien's 'white daddy', with the 35-year-old seeing himself as his son.But all is not well in Mourinho's world. A dramatic win against Newcastle at the weekend papered over the cracks at United. They are eighth in the league, seven points off top.
And there are signs of tension behind the scenes. There may be a mass exodus of players if Mourinho stays in charge, with problems between him and his squad. But for Essien, Mourinho remains the man.
He told Sportsmail: 'For me, Jose is still the same. He hasn't changed. He still has the fighting spirit, he's still going to work hard to change things. For me he is always the same.'He had a very big influence on me and we'll always have this father and son relationship. He's a fighter and a winner and he wants to win. Knowing him he'll do everything to change things.'
There have been suggestions that Mourinho's methods do not work for the new generation of footballers. Why would brand Paul Pogba, for example, face criticism in the press when he is arguably more marketable than the club itself?
When it is put to Essien that the modern-day player would not react as well to Mourinho's methods, he puts down his bottle of Supermalt, nods and says, 'Probably you are right.'My time at Chelsea under Jose, I mean sometimes he goes hard on us to get the best out of us, we'd go there, go back and change things.
'Maybe... probably things are different. At the end of the day it's football. As a player you know if you're not playing well. You want to go back and try to change things.
'With me, it worked very well. Everyone is different. Players are very different, every player is very different to every other one. We'll see how things go.'
Essien was probably the perfect Mourinho player, willing to sacrifice himself for the team. There was no hint of individuality where he was concerned, and that was probably a blessing in terms of their dynamic. 'His message was always clear,' he added. 'I want you to do this and I'd go out there and do it.
'I've got the talent, I just do what the manager says, that's all I've done my whole career. That's his decision, you have to follow what he says.'
Essien is sat here in Brick Lane doing promotional work around the Champions League, the trophy he won against Bayern Munich in 2012. Managerial strife had defined that season, with Andres Villas-Boas, touted as the next Mourinho, sacked by Chelsea and replaced by Roberto Di Matteo.
Chelsea had seemed down and out but managed to turn around a tie against Napoli before a shock win at the Nou Camp: 'When the return game against Napoli happened, we said anything can happen.
'We just had to go in, work hard, do our best and see what happened. That took us through to the final. We won it in Munich, their home ground - that was a special day for us.'
It seems obvious, but while looking back on his playing career - which Essien has technically not called time on - it becomes clear that the Ghanaian adores the sport.
Manifesting itself in the way he plays with the new blue Champions League ball on the table in front of him, he says: 'I just love playing football. Football is everything for me. I was lucky enough to play for some big clubs.'
Laughing, he adds: 'It looks good on my CV, I guess?'
He is still visiting Chelsea's training ground on a regular basis, but not to coach. He pops down to Cobham if he fancies a game: 'I still play sometimes. I still train sometimes with the Chelsea kids. I go down to play with the Under 23s, to train with them.' Even now, the influence of Mourinho runs deep. He has an appreciation for what Maurizio Sarri is now doing at Chelsea. He views them, Liverpool and Manchester City as the likely candidates for the Premier League title.
All aesthetically brilliant, but he only had one goal in mind when he went onto the pitch: 'Winning is all that matters really. I would not really be happy to play good football and lose - I wanted to play well and win or play bad and win.'
Essien admits he is hoping results pick up at Old Trafford too, whether performances come or not. At the least, it might stop the Mourinho-led interrogation.