The day before you plan to serve the dish, prepare the buckthorn jam. Place the sugar and juice into a pan and bring to the boil. Turn down to a simmer and reduce until you are left with around 275g (around 10 minutes). Pour into a jar and place in the fridge to set and chill

While the jam is setting, make the bavarois. Place the mango purée, milk, egg yolks and sugar in a pan and warm to 80°C, stirring constantly. Squeeze the gelatine to remove excess liquid and add to the hot mixture, stirring to dissolve. Pour the mixture into a bowl set over iced water and cool to 40°C

While the mixture is cooling, whip the cream to soft peaks. Once the mango mixture hits 40°C, gently fold in the cream and pour the mix into 4 spherical silicone moulds which are 3cm in diameter. Place in the freezer for an hour to set (but do not allow to freeze solid). Using a melon baller, scoop the centre out of each bavarois and fill the cavity with sea buckthorn jam. Place in the freezer overnight

Make the meringues the day before you plan to serve the dish too. For the caramelised meringue, place the sugar in a pan and place over a medium heat until it melts and turns a golden colour. Carefully pour in the hot water and cider vinegar, then bring to 121°C

Meanwhile, whisk the egg whites using a stand mixer or a handheld electric whisk until just starting to foam. When the caramel mixture reaches 121°C, slowly pour it into the eggs with the whisk still running. Continue to whisk until the mixture has cooled to room temperature, then transfer to a piping bag

For the ash and white meringues, follow a similar process. Bring the sugar, water and cider vinegar to 121°C in a pan whilst whisking the egg whites until foamy. Drizzle in the hot liquid with the whisk still running until the meringue forms and cools to room temperature

Divide this meringue mix into two and place one-half into a piping bag. Weigh out 2g of hay ash and stir this into the other half of the Italian meringue, then place this in another piping bag

You should now have 3 piping bags each full of a different meringue (white, caramelised and ash). Pipe small circles of each onto a baking tray lined with greaseproof paper and place in an oven set as low as it can go with the door open overnight (or use a dehydrator if you have one)

The next day, place the diced mango in a bowl and pour over the sea buckthorn juice to marinate. Set aside until ready to plate

Lightly crush the meringues and mix the three colours together to create a gravel-like consistency

Make the mango jelly by placing the purée and sugar in a pan and gently warm until dissolved. Mix in the gelatine and bring to 40°C

Take the bavarois out of the freezer and remove from their moulds. Smooth down and lines made by the seal, then insert a cocktail stick into the base of each one. Dip them into the warm mango jelly for 30 seconds, ensuring they are completely covered, wait a few moments for the jelly to set and then transfer them to 4 plates. Leave for 10 minutes to come up to room temperature

To serve, place cubes of fresh mango and three small dollops of sea buckthorn jam around one side of the bavarois. Top with a good amount of the crushed meringue, then garnish with the salty fingers and sorrel