Mix together the milk, cream and sugar in a saucepan and then add the vanilla essence. Place the elderflower heads in the pan, heads first into cream mix (you could always wrap the elderflowers in muslin first but I like it when some of the flowers fall off and go into the cream) or the cordial, if using. Place the saucepan onto the hob and bring the mixture just up to the boil then take it off the heat. Cover with a tea towel and set aside for half an hour or so, to allow the flavours to infuse and then gently lift out the elderflowers

Soak the gelatine in a bowl of cold water for 5 minutes, until it goes all soft and squidgy and then squeeze the out excess water

Place the saucepan back on the hob and gently reheat and then add gelatine. Stir well with a whisk until all the gelatine has dissolved. Leave to cool to room temperature and then once cool, pour the mixture into 4 small moulds, such as ramekins (I used some pretty scalloped pastry tins). Chill in the fridge for at least 4 hours, until set

Meanwhile, poach your rhubarb in a wide saucepan with just a splash of water and the sugar for 3-4 minutes. You don’t want your rhubarb to go mushy. Once cooked through, leave to cool completely and then chill

Turn out your panna cottas but dipping each mould very quickly in hot water, very quickly otherwise your panna cottas will melt. Then turn upside down onto the middle of a plate and give it a tap and a shake. Spoon some of the rhubarb batons on top of the panna cotta and then drizzle a generous helping of remaining syrup around the outside. Garnish with two mint leaves