Jerusalem artichoke and potato bake with Welsh rarebit topping

Method

1. Preheat oven 200°C/fan180°C/gas 6. Cook the artichokes in a pan of boiling water for 5 minutes. Add the potato slices to the pan and cook for a further 5 minutes. Drain and toss the potato and artichokes in the flour.
2. Meanwhile, heat 1 tbsp oil in a frying pan over a medium-low heat. Add the red onion and fry until soft.Add the garlic and fry for 1 minute. Put in a bowl. Add the butter and a splash of oil to the pan and sauté the leeks until golden. Add to the bowl with the thyme and nuts. Layer the artichoke and potato, onion mix, and two-thirds of the cheese in a 3-litre ovenproof dish, seasoning as you go.
3. Mix the cream and stock together. Pour over the potato bake and sprinkle with the remaining cheese. Bake for 30 minutes until tender.
4. Meanwhile, for the rarebit, melt the butter in a pan until foaming. Add the flour and cook for 1 minute. Off the heat, slowly add the milk, then the cheese, mustard, ale and Worcester sauce, and stir until smooth. Cool a little, then stir in the egg yolks.
5. Preheat the grill to medium-high. Toast the bread, then lay on top of the bake. Pour over the rarebit mixture and grill until golden and bubbling.