Preheat oven to 375°F or 190c
Place salt, water, sugar (if using) and butter in a saucepan and heat over medium heat, stirring occasionally. When the water is just starting to boil (butter should be melted at this point), add the flour in one go (do this with the saucepan away from the stove/heat) and vigorously mix the flour in so that it absorbs all of the water (use a wooden spoon or spatula to do this). When the flour has absorbed the water and it’s forming a dough, return the pan to the stove (medium heat).
Cook the dough for 2-5 minutes while you mix and move it around in the pan until you get a dough that pulls away from the sides of the pan, forms oil droplets on the surface and when you stick a spoon in the dough, it stays upright.
Transfer the dough to a bowl, and let it cool down slightly for a few minutes. With a hand held mixer (or whisk), mix the dough while adding the eggs one at a time, mixing well after each addition. Make sure the eggs are lightly beaten so that you can stop adding eggs immediately, when you reach the right consistency – a dough with a glossy sheen with pipeable consistency. You may not use all the eggs.
Prepare a baking tray with parchment paper and mist the surface with water (either using a mister or lightly sprinkle water with your hands –
Pipe the desired shape on to the baking sheet – either using a piping bag fitted with a large tip (I use Wilton 1A or 2A tip, or you can cut the pastry bag opening instead), or spoon it on to the tray, using a teaspoon. Then with a damp finger, flatten the apex and any points.
Bake in preheated oven for 30 – 40 minutes in the center of the oven, or until the choux pastry shells puff up and are golden brown on top. Do not open the oven door at least till you have reached the 25 minute mark. Importantly, baking time depends on the size of your pastry shell. Bake for a couple minutes longer, if you prefer a drier shell.
Remove from the oven, and prick each shell with a toothpick and let it cool completely.
225 g water
¼ teaspoon sea salt
¼ teaspoon sugar
1 fat clove garlic, peeled and grated
400g chestnut mushrooms, wiped and thickly sliced
50ml white wine
1 teaspoon porcini
300g cooked spinach
6 scrapes fresh nutmeg
Salt and pepper to taste
200ml double cream or crème fraiche
1 tablespoon cornflour mixed with 3 tablespoons water to thicken the sauce