Preheat oven to 210°C. Line a baking sheet with non-stick baking paper, and draw a 20cm circle in the centre of the paper. Flip the paper over so you are not piping directly onto it.
To make the choux pastry, place the butter, milk and water in a medium saucepan over a medium heat. Turn down the heat and add the flour and icing sugar, and beat with a wooden spoon until the mixture comes away from the sides of the pan. Remove pan from the stove and cool for a few minutes.
Lightly beat 4 eggs in a small bowl, then add a little at a time to the pastry mixture, beating well between additions. Spoon the dough into a large piping bag fitted with a plain 2cm round nozzle.
Slowly and carefully pipe one ring over the circle you drew on the baking paper, and one directly inside that circle, so they are touching. Then pipe another two circles directly onto over the first two. Smooth out any bumps with wet fingers.
Lightly beat the remaining egg and brush over the dough circles.
Bake for 15 minutes, then reduce the oven to 190°C, and bake for 30 minutes. Turn off the oven and cool the choux pastry ring with the door ajar.
To make the filling, use an electric mixer to beat the cream with the vanilla paste and 1 tablespoon of icing sugar, until still peaks form.
Make the icing by mixing 100g icing sugar with 1 tablespoon of water. Whisk until smooth and set aside.
Using a bread knife, split the choux wpastry ring in half horizontally. Place the base ring on a serving plate. Dollop the cream over the base ring and top with strawberries. Top with the pastry lid.
Drizzle the prepared icing over the top of the pastry lid, and scatter over toasted almond flakes. Dust with remaining icing sugar and serve.