Instructions

1. Preheat the oven to 200°C/180°C fan/400°F/ gas mark 6.
2. Peel and thinly slice the vegetables (I do this in my food processor to save time).
3. Scatter a third of the vegetables in the ovenproof dish. Top with a third of the garlic and thyme, ¼ tsp salt and lots of freshly ground pepper. Then add half the bacon and half the walnuts.
4. Repeat step 3. Then top with the remaining vegetables, garlic, thyme, ¼ tsp salt and lots of freshly ground pepper and then cover the dish in foil. Bake for an 1¼ hour or until all the vegetables are tender.
5. Remove the foil and pour the cream over the top of the gratin. Put back in the oven for 30 minutes or until the top is lightly browned.