In your large saucepan, bring your stock to the boil and then add your potatoes and celeriac.
Reduce to a rolling simmer and cook the potato and celeriac for no longer than 7 minutes.
Now remove from the stock and leave to cool.
Preheat your oven to 200 degrees Celsius.
Meanwhile, add you garlic, capers, anchovy and oil, saffron, lemon juice and dill to your oven dish.
Now add 2-3 tablespoonfuls of your stock, the salt and pepper and mix everything together.
Add your potatoes, celeriac, capsicum peppers and green beans. Sprinkle with your plain flour.
Gently mix everything together so that the vegetables are coated and the flour is thickening the sauce.
Pour around 300 millilitres of stock over your vegetables, gently mix and place in the centre of your preheated oven for 30 minutes.
After 30 minutes, remove from the oven and add your fish chunks. You can add more stock at this stage if you like.
Place your stew back in the oven for 15-18 minutes, depending on the size of your fish.
Serve immediately, garnished with freshly chopped dill and parsley.