Choux Pastry

1. Preheat the oven to 230°C
2. Line a baking sheet with parchment paper
3. Heat milk, water, butter, salt and sugar in a medium saucepan over medium low heat
4. When it starts to boil remove from heat and add the flour in one go, mixing vigorously until smooth
5. Return to heat and flatten the dough to the bottom of the pan, listening for crackling of the dough without mixing
6. Give the pan a shake and when you notice a thin film on the bottom of the pan the dough is sufficiently dry
7. Remove from heat
8. Using a wooden spoon/spatula beat the dough to let steam evaporate and then cool for 10 minutes
9. Slowly add the beaten egg and stir until the dough is smooth, but still holds structure (the batter will form a 'V' or a 'beak' on the spoon/spatula when lifted)
10. Fit a pastry bag with a medium-sized round tip and fill with the batter
11. Pipe 3cm /1.2 inch round mounds onto the lined baking tray
12. Turn down the oven temperature to 160°C and bake for 25 minutes, or until golden brown
13. Remove from oven and poke a hole in the bottom of each puff to release steam
14. Cool on a wire rack

Creme Patissiere

1. Heat milk until just boiling in a small saucepan
2. Meanwhile, in a medium-sized mixing bowl combine egg yolks and sugar, whisking until doubled in volume
3. Add the cornflour and mix until combined
4. Pour the hot milk mixture into the egg mixture and whisk until smooth
5. Return the mixture to medium-high heat and whisk constantly until thick
6. Remove from heat and add butter
7. Pour into a bowl and cover with plastic wrap, ensuring it touches the surface of the pastry cream
8. Cool in fridge until use

Diplomat cream

1. Whisk the cream until medium-stiff peaks are reached
2. Add the cooled creme patisserie and whisk until stiff peaks are reached
3. Transfer to a piping bag with small round tip
4. Reserve in the fridge until use

Assembly

1. Poke a hole at the bottom of each choux puff
2. Fill the choux with the creme diplomat
3. Place in the fridge as you prepare the caramel

Caramel

1. Combine the sugar and water in a small saucepan over medium heat
2. Heat the sugar, swirling the pan occasionally to ensure even heating
3. Continue to heat the sugar until it turns a golden brown
4. Remove from the heat and working quickly dip the tops of your filled puffs into the caramel
5. Place the dipped choux caramel side up on a baking tray lined with parchment paper and allow to set
6. Prepare a styrofoam cone or paper cone made from cardboard (25cm tall x 10cm wide / 10 inches tall x 4 inches wide), wrap it in cling wrap, and place it on your desired serving platter 
7. Dip your filled puffs into the caramel and start to assemble the croquembouche, starting from the bottom and working your way up to the top (if your caramel has hardened up, heat it gently over the stove on low heat until it has softened)
8. Decorate as desired and enjoy!!