Start by splitting the vanilla pods and scraping out the seeds. Add the pods and seeds to the saucepan with the milk and cream and bring to the boil. Reduce to a gentle simmer and cook until the mixture thickens to the consistency of thin natural yoghurt, this will take about 20 minutes.
Remove from the heat and leave to infuse for 5 minutes before adding the drained, soaked gelatine and sugar.
Whisk to dissolve and allow to cool. Strain the cool mixture through a fine chinois and add a dash of grappa to taste.
Chill the mix until almost starting to set before pouring into 6 ramekins. Transfer to the refrigerator and leave until fully set.
To serve, quickly dip the outside of the moulds in hot water and turn out the panna cottas onto plates. Garnish with the strawberries, mint leaves and a little drizzle of grappa