Amanda Roocroft is one of this country’s most sought-after sopranos, having appeared at most of the major opera houses throughout the world, but unlike many singers who build their careers by steadily progressing through the ranks of the chorus and taking on small roles, her appearances in the student performances at the RNCM were so ‘complete’ that critics were left stumbling over themselves searching for superlatives to describe her performances.

Such was the ‘buzz’ around Amanda that she found herself being catapulted to stardom at a very tender age, so I was keen to find out what that felt like. “It’s like a lifetime ago – it was shocking, surprising, not at all what I expected, but most of all bewildering and exciting.”

Most singers her age, as she readily admits, were expected to join the Glyndebourne Chorus, cover roles for more established singers, and would then be gradually assigned small parts, but Amanda found herself cast as Fiordiligi in Cosi fan tutte at Glyndebourne, “I was lucky to be working with really top notch directors, conductors and singers from an early age such as Trevor Nunn and Simon Rattle on Cosi. It was the most amazing experience for me and formed in my mind what great opera making should be – a fantastic director, a fantastic conductor – marry the two together and that’s what I thought all opera should be like.”

Amanda admits that she was lucky to have such an amazing start to her professional career, but also reminds me that it’s “just a job”, something that her supportive family have kept reminding her over the years, which is probably why she comes across as being so genuine and grounded in the short time that we have together at the Coliseum. When I ask her about her career-defining roles she’s quick to tell me that she sees her career in three clearly-defined stages, “There was a leaving college period, then there was a period when I was on a crest, then I took a dip, and then I took on a new life four years ago and started a new crest.”

Many singers find that there’s a lull in their career or they fall out of favour with critics and audiences alike but Amanda is very candid in telling me that her ‘dip’ was due to the fact that she stopped enjoying singing and that there were “so many factors going on at the time and it’s hard to say which affected me most but I began to fear singing. I began to hear my voice as being ‘ugly’ and didn’t enjoy the whole thing.”

She was singing Katya and Butterfly at the Royal Opera, Butterfly and Tatiana with WNO, yet as she points out “they were all career-defining moments, yet I was beginning to doubt and question – as I had done throughout my career - whether this was the path that I wanted to follow.”

Things were hard in her home life as well and the maxim that her singing teacher had given her - every emotion shows through your voice rang true. She felt sad and this showed in her singing. However she decided to do some “spring-cleaning” in her life, so she looked at her life and questioned what she did need and what she didn’t need and as she says. “Here I am”.

It was her searing portrayal as Jenufa in David Alden’s highly-acclaimed staging of Janacek’s opera with ENO in the autumn on 2006, that proved to be pivotal in the direction her career and life would take. Although none of her colleagues knew it at the time, Amanda had decided that she was going to give up singing after the run of performances and re-train as a primary school teacher. She describes this decision, along with a better home life and her becoming a Christian, as being like a huge weight being lifted from her shoulders. Thankfully the love of singing returned, critics and audiences alike were calling her performance definitive and she rightly went on to win the Olivier Award for most outstanding opera performance.

Much of her success as Jenufa she puts down to working with David Alden whom she loves, and like every other singer you talk to who has worked with him can’t find words to praise him highly enough. Now she is about to take on the role of another great Janacek heroine, the enigmatic Emilia Marty in The Makropulos Case and considers herself fortunate to be working with David’s twin brother Christopher for the first time. When she first told people that she was going to take on the role everyone reacted by saying “Oh – and they had those raised eyebrows, so I thought ‘what’s going on’?” But she read the play, looked at the score and became intrigued by the character. “She’s an operatic diva but is filled with such bitterness – it’s only at the end of the opera that the audience should go ‘Ah, so that’s why she behaved the way she did...’”

As she explains, Emilia Marty was basically raped of her youth by her father and raped of any kind of normal existence, “she’s watched her children die, her lovers die and has become more and more incapable of allowing herself to become vulnerable – her life is pointless and it’s so sad.” Amanda agrees that it’s a gift of a role to sing, and given her total commitment to all the roles she assumes on stage, her role debut as Emilia Marty promises to be not only a highlight of the season, but unmissable as well.

The Makropulos Case opens at the London Coliseum on Monday 20 September for five performances. www.eno.org