Preheat the oven to 190ºC/Fan 170ºC/Gas 5. Ensure you have a shallow ovenproof dish on hand, approximately 20 × 28 × 5cm (8 × 11 × 2 inches) in size.
Pour the water into a saucepan.
Add the chopped onion and the apricot pieces, bringing the mixture to a boil.
Allow it to simmer for 5 minutes, then drain it thoroughly.
Melt the butter in a non-stick frying pan,
Place the breadcrumbs into a generously sized bowl and then pour half of the melted butter over the breadcrumbs.
Add the chestnuts into the frying pan with the remaining butter and lightly brown them.
Combine these chestnuts with the apricots, onion, parsley, and buttery breadcrumbs.
Season the mixture well with salt and pepper.
Transfer this flavorful mix into a buttered ovenproof dish, and slide it into the preheated oven.
Bake it for approximately 30 minutes, or until it achieves a delightful crispiness.