For the panna cotta: Soften gelatine in cold water.
Cut vanilla pod lengthwise and scrape out seeds. Boil pods, seeds, milk, cream, sugar and lemon zest together. Remove from heat, squeeze gelatine well and dissolve in warm milk. Remove vanilla pods and lemon zest. Cool milk in a cold water bath, stirring constantly. Once milk thickens, stir well again and pour into a mold, preferably a clover leaf shape, that has been rinsed with cold water. Cover and chill for 4-5 hours.
Rinse and pat dry raspberries. Peel, core and dice pineapple.
Remove panna cotta from refrigerator and carefully turn over onto a plate. Garnish with fruit, mint and chopped pistachios. Serve immediately.