Step 1

Heat the oil in a large casserole over a medium heat and add the leek and celeriac. Season with salt and pepper, put the lid on and cook for 7–8 minutes until softened.

Step 2

Meanwhile, place half of the beans in a small blender with 300ml/10fl oz hot water.

Step 3

Add the vegetable stock cube and blitz. The mixture should be fairly loose. Add the mixed herbs, fennel seeds (if using) and blended bean mixture to the leek mixture and bring to a gentle simmer. Stir in the cornflour to thicken the mixture.

Step 4

Add the mixed vegetables, fish chunks and remaining beans and cover with a lid for another 5–8 minutes to cook through. At this point, preheat a grill to medium–high. Remove the lid of the casserole and scatter with the crumbs. Drizzle with olive oil, sprinkle with some salt and pop under the grill for 2–3 minutes until golden and bubbling. Remove from the heat and leave to stand for a few minutes before serving.