Butternut Squash Gratin with Walnuts & Sage

Ingredients:

• 900g-1kg butternut squash
• Olive oil
• 2 leeks
• 4 garlic cloves, roughly chopped
• Small handful of fresh sage leaves (around 15), chopped; (plus 10 whole leaves for a crispy garnish – optional)
• 280ml cream
• 1/2 tsp ground nutmeg
• 1/2 tsp onion powder
• 90g Gruyère cheese, grated
• 70g roughly chopped walnuts
• Salt & pepper

Instructions:

1. Preheat oven to 190°C.
2. Peel and slice butternut into 3mm rounds, set aside about 12-15 of the prettiest slices for the top layer.
3. Slice white & green parts of leeks into thin rounds (I use a mandolin) and rinse. Heat 2 TBSP olive oil in a heavy based pan over medium heat. Add sliced leeks and sauté for 8-10 minutes, stirring occasionally until they have softened. Add garlic, chopped sage, pinch of salt and cook for another 2-3 minutes. Set aside.
4. In a bowl, whisk the cream with 1/2 tsp salt, 1/2 tsp pepper, 1/2 tsp ground nutmeg and 1/2 tsp onion powder.
5. Grease a 20x30cm baking dish or 28-30cm round dish. Add 60ml water to the bottom of the dish.
   • Arrange a first layer of butternut slices, slightly overlapping. Top with half of the leeks, 1/3 of the cream mixture and sprinkle with 1/3 of the grated Gruyère.
   • Repeat with another layer of butternut, followed by the rest of the leeks, 1/3 of the cream and 1/3 of the cheese.
   • Add the final layer of butternut slices. Press down to level the gratin if it domes up. Drizzle with the remaining cream and then sprinkle with last cheese and chopped walnuts.
6. Cover dish with baking paper, then cover tightly in foil to stop the top of the gratin sticking to the foil. Bake for 45 min, then uncover and bake for another 15 min at 200°C until the top is golden, the butternut squash is tender and most of the liquid has evaporated.
7. Optional: For an extra touch, heat 1-2 TBSP olive oil in a small pan over medium heat. Fry 10 whole sage leaves for about 30 sec on each side until crisp. Drain on a paper towel and arrange them on top of the gratin.