Preheat your oven to 220C / 200C Fan. Prepare a large baking sheet.
Sieve your gluten free self raising flour, xanthan gum, sugar and salt into a bowl. Put to one side.
Place your milk and water into a small/medium saucepan alongside your butter. Heat on a low/medium heat until the butter has melted.
Once melted allow to bring up to a gentle simmer. Once simmering, turn the heat off and immediately add your flour mix to the saucepan. Mix vigorously straight away until everything comes together into a dough.
If the mixture still seems a tiny bit moist on top put it back on a very low heat (continuously stirring) for a minute or so, don't let it stick to the bottom.
Take off the heat and place in a bowl to cool a little. You need to do this before adding your eggs next.
Beat 2 eggs in a jug and then gradually add it to the dough. You need to mix really thoroughly between each addition. You can do this by hand quite easily but its a proper workout! I tend to do it with an electric hand mixer on the lowest setting. It doesn't look the prettiest whilst mixing but keep going until smooth.
Make sure you are watching the consistency of the dough as you add the egg. You don't want it to go too runny. It needs to be thick enough to be a pipeable consistency that can hold it's shape.
At this point the dough should be ready to pipe. Transfer your dough into a piping bag (I use a 1A nozzle). Pipe small balls onto your baking sheet with a little space between each ball. I make about 15 with this amount.
Once they've all been piped, wet your finger and dab the top of each ball to help with the shape. Gently flatten any pointy bits.
You can gently brush a little egg or milk on top of each ball but only if you have some spare as it's not necessary.
Place in the oven at 220C / 200C Fan for 10 minutes. Then reduce the temperature of the oven to 170C / 150C Fan for a further 15 minutes until puffy and golden. Never open the oven until they are ready to be taken out.
Remove from the oven and pierce the bottom of each profiterole with a skewer and place them upside down to let the steam out, otherwise they will be soggy inside. Allow to cool down in a warm area - I usually do this by putting them back in the oven, turned off with the door ajar - do this for about 20 minutes.
Store in an airtight container if you aren't planning to use them immediately.