Ingredients:
For the pie:
1/2 cup olive oil, plus more for greasing the pan
8 garlic cloves, roughly chopped
2 tablespoons tomato paste
1 tablespoon cumin seeds, roughly crushed in mortar and pestle
1 tablespoon coriander seeds, roughly crushed in a mortar and pestle
2 teaspoons Aleppo chilli flakes
1 (12 ounce - 340 gm) jar red peppers, drained
1 teaspoon light brown sugar
Fine sea salt and black pepper
1 small butternut squash (about 1 3/4 pounds - 800 gm approx) peeled, halved, deseeded and cut into 1/8 inch thick slices
8 oz dried lasagna noodles, each roughly broken into 3-4 pieces
7 oz baby spinach (10 lightly packed cups)
1 packed cup basil leaves, torn in halves
1 cup crumbled Greek feta
Heaping 1/2 cup finely grated Parmesan
For the Bechamel
3 tablespoons unsalted butter
1/3 cup all-purpose flour
1 1/2 cups whole milk, plus more if needed
2 garlic cloves, minced
Fine sea salt
1/4 cup finely grated Parmesan
Preparation:
Make the pie: Heat the oven to 400 degrees (204.4 C). Grease a 9 inch springform cake pan, then line it with a piece of parchment paper large enough to cover the base and hang over the sides by a couple of inches. Set aside.
Add the oil to a small frying pan and heat over medium-high. once it's hot, add the garlic and cook for about 1 minute, stirring until fragrant but not browned. add the tomato paste, cumin, coriander and chilli flakes and cook for 1 minute more, stirring often until deeply red. Set aside to cool slightly, then add to a small food processor with the red peppers, sugar, 1/2 tsp salt and a good grind of pepper. Blitz until smooth.
Empty the mixture into a very large bowl and add the squash, lasagna sheets, spinach, basil, feta, Parmesan, 1 1/4 tsp salt and a good grind of pepper. Use your hands to make sure everything is nicely coated. Transfer this mixture to your lined cake pan, adding a third at a time, and pressing lightly to ensure everything is even and compact. Using heavy duty aluminium foil, wrap the cake pan all around until tightly sealed, place on a baking sheet and bake for 1 hour.
Towards the last 15 minutes of baking time, make the bechamel. Melt the butter in a medium saucepan over medium-high heat. Whisk in the flour and cook, whisking steadily for 2-3 minutes, or until it starts to smell like popcorn. Slowly pour in the milk 1/2 cup at a time, whisking with each addition until fully incorporated. Turn the heat down to medium then add the garlic and 1/4 tsp salt. Use a spatula to stir and cook for 2 minutes, stirring to ensure the bottom doesn't scorch, until nice and smooth. Off the heat, stir in the Parmesan. If the pie isn't done, cover the top with a piece of parchment paper to prevent a skin from forming. The bechamel is easier to handle when warm; if needed, re-heat gently with a splash of milk to loosen.
After the pie has cooked for 1 hour, remove it from the oven and carefully unwrap the top foil and paper, crinkling it down and around the sides of the pan to expose the top. Spoon the bechamel on top, using a spatula to distribute it evenly over the surface. (Take care not to mix it with the base, you want the bechamel to remain white.)
Turn the over temperature up to 450 degrees F (232.2 C), place the cake pan back on its baking sheet, and bake for another 15-20 minutes, till nicely browned on top. Set aside to cool for at least 15 minutes.
Carefully release the pie from the springform pan, loosening the outer ring then using the parchment to help lift it onto a serving plate or board. Serve warm or at room temperature.