Instructions

1. Preheat the oven to 375F / 190C.
2. Make the béchamel: Warm the milk in a medium saucepan over medium heat and set aside. In a separate saucepan over medium heat, heat the olive oil and as soon as it starts to sizzle a little, add the flour. Whisk continuously for 3 – 5 minutes to form a roux, do not brown the flour. Slowly add the warm milk, whisking all the while. Continue to whisk the béchamel until it thickens but is still liquid. It should be the consistency of pancake batter.
3. Season with salt, pepper and nutmeg. Pour in the egg in a fast, steady stream, whisking vigorously. Stir in the grated cheese. Set the béchamel aside, covered with a kitchen towel.
4. Cook the pasta: Bring a large pot of water to a rolling boil, salt generously and add the pasta. Cook until al dente. Drain immediately and toss with 2 tablespoons of olive oil.
5. Make the filling: In a large, deep skillet heat the remaining 2 tablespoons of olive oil over medium heat and sauté the leeks until translucent. Add the garlic and stir for a minute to soften. Add the spinach, in increments if necessary, and sauté until wilted and until most of the liquid it exudes has cooked off. Remove from the heat. Mix in the cheeses and dill, if using, and season to taste with salt, pepper and nutmeg.
6. In a large mixing bowl, stir together the elbow pasta, spinach mixture and béchamel.
7. Spoon the mixture into an oiled casserole dish and sprinkle the top of the spanakopita mac ‘n’ cheese with additional grated cheese if desired and with the breadcrumbs. Bake uncovered for 30 minutes, or until set and golden.
8. Remove, cool slightly and serve.
9. Note: You can use skim, whole or even goat's milk to make the olive oil bechamel, and you can make the bechamel and the filling a day or two ahead of time and assemble the mac 'n' cheese the day you plan to cook it.