https://www.bbc.com/news/uk-england-london-45617845Natasha Ednan-Laperouse, 15, collapsed during a flight from Heathrow to Nice on 17 July last year.
Despite her father administering two EpiPen injections, Natasha, from Fulham, London, died within hours, West London Coroner's Court will hear.
Pret a Manger said it was "deeply saddened" by the death.
Natasha's father, Nadim Ednan-Laperouse, said in a statement: "It's a daily battle and the pain is indescribable."
Mr Ednan-Laperouse, the founder of Wow Toys company, said: "As a family now of three, my wife, son and I are still trying to adjust to life without our beloved girl.
"Everything we say and do is a reminder that she isn't with us - her empty bedroom, school uniform hanging in her wardrobe, her holiday bag packed for her holiday in Nice has never been unpacked. We can't bear to."
A spokesperson for Pret said: "We were deeply saddened to hear about Natasha's tragic death, and our heartfelt thoughts are with her family and friends."
Image caption Natasha had eaten a baguette just before boarding the flight to Nice
Natasha ate an artichoke, olive and tapenade baguette bought from the main Pret a Manger shop in Terminal 5 at Heathrow airport, said the family's solicitors, Leigh Day.
It is believed the sesame was baked into the baguette, rather than contained in seeds on its crust, said Pret.
The teenager collapsed on the British Airways flight and later died in hospital in Nice.