Queen Elizabeth II will celebrate her 90th birthday on April 21. But, her official birthday weekend will be celebrated with a Patron’s Lunch on June 12. The event organized by her grandson Peter Phillips will witness 10,000 people participate on the Mall for a picnic-style lunch.

The Patron’s Lunch, which is being pitted as the biggest street party, is being held to celebrate Elizabeth’s milestone birthday and her patronage of over 600 charities and organizations. It is being organized by Phillips and his company SEL. Tables will be laid out along the full length of The Mall.

Guests will also be treated to a carnival parade down The Mall and along Birdcage Walk. The British royal and her husband Prince Philip will attend along with other members of the royal family. The not-for-profit event will raise money for the newly created Patron’s Fund, which supports Elizabeth’s charities in the U.K. and Commonwealth.

However, the most awaited part of the street party and the Patron’s Lunch is the elaborate menu — a custom made Marks & Spencer wicker hamper that each guest will get. The delectable treats include a smoked salmon mousse with hot and cold smoked salmon. It will be made with Scottish Lochmuir salmon, smoked over wood chips from an oak tree grown on Elizabeth’s Sandringham Estate in Norfolk.

Also in the menu feature a chicken roulade salad, created using roasted free-range meat from Pembrokeshire, Wye Valley asparagus and Cornish potatoes. There are sandwiches roast Northern Irish beef with horseradish and baby watercress and a mini piccalilli pork pie.

The pie has been hand-crafted by expert bakers in Melton Mowbray, with a “Posh” raspberry Royale for dessert made from fruit grown in Norfolk. The lunch and afternoon tea will come in a wicker basket along with a blue plastic plate, a matching set of plastic cutlery, a plastic wine tumbler and a napkin. Drinks in the bespoke hamper include a 250ml can of Pimm’s, a 500ml bottle of M&S Scottish spring water and a bottle of Windsor apple juice  produced with fruit grown in Suffolk.

Desserts include two butterfly cakes — one light vanilla sponge cake with strawberry frosting and the other a lemon cake topped with lemon frosting. There is also a Cornish cove mature cheese and red Leicester with Scottish seeded oatcakes. Tickets for the event cost 150 pounds.

“The Patron's Lunch Hamper has been created by our food experts who have put all their passion and creative know-how into devising a very special menu for the celebration. We’ve worked closely with farmers and producers to ensure we showcase the very best of British produce at The Patron’s Lunch and we’re looking forward to seeing guests enjoying the picnic on The Mall,” said Sandra Ziles, Head of M&S Product Development.