100g dark chocolate (70% cocoa)
3 egg whites (or equivalent of pasteurised egg whites)
Break the chocolate into squares and heat in the microwave on HIGH for 30 seconds. Poke around and microwave again for another 30 seconds. Let it rest for a moment and then stir - it should be molten but if not give it another 30 second blast. Put the melted chocolate to one side.
In a large bowl, use a handheld electric whisk to beat your egg whites until they form stiff peaks. Your chocolate should now have cooled a little so stir in one large spoonful of the egg whites to lighten the mix. (If the mixture suddenly seizes up and goes grainy, your chocolate is too warm still. Don't panic! Add a splash of water or non-dairy milk and stir gently until it loosens back up and goes smooth again).
Take the lightened chocolate and pour into the bowl with the egg whites. With a large spoon gently fold the two mixtures together until just combined.
Spoon the mousse into 4 little ramekins and leave to set in the fridge for at least 3 hours.
The only limit is your imagination really - you can add orange zest, cinammon, cardamon, chilli, peanut butter etc - whatever takes your fancy so long as it is allowed on the FODMAP diet plan. The versions below are my favourites as both mint and ginger are good at soothing IBS.
Mint-choc - add a drop of peppermint essence to the melted chocolate and serve scattered with mint leaves. You can also try adding crushed mint sweets/candies to make it mint-choc chip. Stir them in when you fold in the egg whites.
Dark chocolate ginger - add 2tsp ground ginger to melted chocolate.
Hazelnut - add 1 tablespoon hazelnut liquor (such as frangelico) to the melted chocolate and garnish with toasted, chopped hazelnuts.