The firm began its search back in November 2010, when it called for favourite vegetarian recipes from budding chefs across the country. By January 2011, hundreds of entries had been received and the judging panel met in February to taste the shortlist and select three finalists.
The judging panel was hosted by Mary McCartney and included chef Aldo Zilli, Celebrity Masterchef winner Liz McClarnon, Green & Black's co-founder Josephine Fairley, the Vegetarian Society's Alex Connell and Sainsbury's category buyer Alison Atkin.
The Linda McCartney Foods team later visited the three finalists' hometowns to create a mini-documentary of each finalist cooking their dish, which aired during ITV's This Morning between April 411 2011.
The winning recipe, by Kate Ford, was chosen through the public's online voting system on itv.com.
Kate's pie is cooked with flaky puff pastry and has a filling of mushrooms, lentils, onions and ale. It has inspired the new Linda McCartney Foods product that will hit Sainsbury's shelves nationwide this month.
Sir Paul McCartney said: "The meat-free way of life is tasty and environmentally friendly. Kate's pie has all the values Linda cherished: hearty, home-cooked and meat-free."