Preheat the oven to 160 Fan / 180 C / 350 F / Gas 4 and rub a drizzle of olive oil around a baking dish - I used one 5 x 9 inches
Mix the ground flax seeds with the water and set aside to thicken
In a large frying pan, heat another drizzle of olive oil and gently saute the onions, garlic, celery, apple and herbs for around 10 minutes, stirring occasionally till softened
In a medium bowl stir together the quinoa flour and ground almonds
To the frying pan add the flax 'egg' and sultanas and stir, then stir in the quinoa/ground almonds, a few good twists of black pepper and a large pinch of sea salt, incorporating well
Tip everything into your greased dish and put in the oven for 45 mins - 1 hour till firm in the centre
Serve immediately - though it's also just as lovely cold in a sammich the next day too!
Notes
With the best will in the world, fresh herbs aren't always readily available. If not, substitute:
Thyme - 1 tsp dried thyme
Sage - 1 tsp dried sage
Rosemary - 1/2 tsp dried rosemary
Recipe by The Cook & Him at https://thecookandhim.com/recipes/gluten-free-stuffing/