In a saucepan heat water, milk, butter, salt, sugar, and vanilla until boiling; remove from heat and add the flour all at once, stirring vigorously.
Return pan to low heat and cook, stirring, until the dough dries out slightly and pulls away from the pan.
Remove from heat, add the eggs and beat until the dough is smooth and glossy; transfer to a piping bag.
Pipe logs of dough onto a baking sheet lined with parchment; preheat oven to 249°C, place éclairs in oven then immediately lower temperature to 160°C and bake about 40 minutes.
Ganache
Gently melt the white chocolate (microwave or bain-marie) until soft and smooth.
Pour 1 1/29 4/7ml (about 20 g) hot cream over the chocolate, add the drained gelatin, vanilla, and orange blossom water and mix until smooth.
Stir in the remaining cold cream (about 2 2/44 3/8ml, 40 g) until fully combined, cover surface with plastic wrap and refrigerate for 2 hours.
After chilling, whip the ganache with a mixer until it holds stiff peaks; if too firm, fold in a little mascarpone, then transfer to a piping bag fitted with a tip.
Assembly
Cut the tops off the cooled éclairs.
Pipe the whipped ganache into the éclairs to fill.
Top with raspberries, sliced kiwi and red currants as desired.
Sprinkle lime zest over the fruit and serve.
Tips
Use room-temperature eggs and sift flour for a lighter, more consistent choux dough.
Start at high oven heat then lower immediately to set éclairs and avoid collapsing them.
Fill éclairs just before serving and zest lime over fruit to preserve freshness and color.