Picnickers will dine on tea-smoked Scottish salmon, a modern take on coronation Chicken and Sandringham strawberry crumble crunch in the Buckingham Palace gardens today.

Individual hampers will be handed out to 12,000 guests before the Diamond Jubilee concert and will include two cupcakes, cheese and biscuits, and a plastic poncho in case rain dampens the festive proceedings.

The feast was created by celebrity chef Heston Blumenthal, famous for his scientific approach to cooking, and royal chef Mark Flanagan who catered for the Duke and Duchess of Cambridge’s wedding.

Coronation Chicken, created to celebrate the Queen’s coronation in 1953, has been revamped as Diamond Jubilee Chicken and features a blend of spices Blumenthal spent two months developing for a previous television programme about curry.

There is also a vegetarian option, mushroom parfait, a roasted mushroom puree blended with a port, brandy and Madeira reduction, butter and free-range eggs.

A garden soup made with plum tomatoes, cucumber, garden mint oil and vinegar is also in the selection.

Side dishes are seasonal crudités of celery, carrots and red peppers.

Fiona Cairns, who baked William and Kate’s wedding cake, created the two cupcakes, lemon and caraway Madeira cake and a chocolate indulgence cake decorated with a chocolate crown and sprinkled with one of Blumenthal’s favourite finishing touches: popping candy.

The potted salmon includes Lapsang souchong tea-smoked salmon with crème fraiche, lemon and fresh chives, while the Sandringham strawberry crumble crunch is made from a strawberry compote, meringue, whipping cream, natural yoghurt, elderflower cordial and rosewater.

The organic Florence strawberries were grown on the Queen’s Sandringham Estate in Norfolk and harvested and frozen last year in preparation for the picnic.

The cheeseboard has West Country farmhouse cheddar and Red Leicester crunch, served with Duchy Originals from Waitrose chutney and oaten biscuits.

Duchy Originals was founded by the Prince of Wales in 1990.

All dishes were selected to be served cold because of the practicalities of catering to such a large number of picnickers.

Waitrose chefs worked with Blumenthal and Flanagan in developing the menu.

Guests, selected via public ballot, can choose to drink Moet & Chandon champagne, Cobra beer or Hildon’s water.

Backroom staff and organisers also get a hamper to eat during their lunch break.

The picnic container itself will be unveiled for the first time today.

Here are the contents of the Jubilee hamper: Chilled British country garden soup Tea-smoked Scottish salmon Diamond Jubilee chicken Vegetarian option: mushroom parfait Fresh bread rolls Country Life butter Crunchy seasonal crudités Lemon and caraway Madeira cupcake Chocolate indulgence cupcake Sandringham strawberry crumble crunch Waitrose West Country farmhouse cheddar and red Leicester Duchy Originals from Waitrose oaten biscuits Duchy Originals from Waitrose harvest chutney Extras: 12 Hand wipes Clear plastic cutlery and napkin Diamond Jubilee poncho Union flag