A pop-up ‘deli-come-spa’ is due to open in London, offering customers specially created health and beauty sandwiches with an accompanying beauty treatment.

The unique concept was developed by gluten and wheat-free food brand BFree foods, with healthy-eating guru, and future Countess of Sandwich, Julie Montagu. It is set to be situated in La Galleria Pall Mall.

The full menu, which was created by Montagu, features five sandwiches and treatments; Roll Back the Clock, Mindfulness Bites, B.L.T (Beautiful Long Tresses), A Slice of Energy and Good Gut Club.

Roll Back the Clock is an anti-ageing sandwich - the world’s first - that contains anti-ageing ingredients including spinach and sweet potatoes. It is served alongside a vitamin C-rich facial that is designed to revitalise the skin and boost collagen production.

B.L.T is made with tofu and walnuts to restore the body’s keratin levels and strengthen the hair follicles, to improve the hair’s overall appearance. Customers who order the B.L.T. will also receive a stimulating scalp massage.

Mindfulness Bites is a sandwich designed to enhance mood, and includes a mindfulness and aromatherapy session.

A Slice of Energy comes with a neck, shoulder and back massage and is designed to boost energy; and Good Gut Club is a pitta bread filled with ingredients to prevent bloating, served alongside a full body wrap.

Montagu said: "We wanted to create recipes that have considerable health benefits, using ingredients that are good for the mind and body. The anti-ageing sandwich contains ingredients such as buckwheat, which supports cell repair, and spinach - a source of phytonutrients that can help to prevent sun damage and various diseases, all contributing to combat the signs of ageing."

The Sandwich Spa is free to visit and will run from 14 to 16 March.