• In a medium heatproof bowl, pour the boiling water over the cocoa and whisk to combine. This will bloom the chocolate and deepen the chocolate flavour. Set aside to cool a little.
• Melt the chocolate in a medium heatproof bowl using your preferred method. Set aside to cool a little.
• Combine all ingredients in your high speed food processor and blitz until completely smooth. There should be no lumps and no chia seeds - just a smooth chocolate mousse consistency.
• Taste the mixture and adjust according to your preferences. If you add a lot more of a liquid ingredient (namely sweetener) than specified, you might need to add more chia seeds to enable the mousse to firm up.
• When you're happy with the taste, pour the mixture into 4 clean glass jars or serving vessels. Place in the fridge for at least 30 minutes and up to an hour. You should be able to invert the jar upside down without the mousse slipping. You can also make this recipe the day before.
• Eat within a few days. Store leftovers in airtight containers (this is why jars are so useful) in the fridge.

Optional egg white addition:

• Once you have made the mousse, transfer it into a large mixing bowl. Use hand beaters or a stand mixer to whip the egg whites until soft/medium peaks form.
• Use a silicon spatula to gently fold the egg whites into the chocolate mixture. Continue gently folding until they are incorporated and there are no big chunks of egg white.
• Pour the mixture into your serving vessels and refrigerate for at least 30 minutes. You can also make this recipe the day before.