Ingredients
For the Lamb Sauce
- 900 g (2 lb) ground lamb
- 30 mL (2 tbsp) canola oil, divided
- 1 yellow onion, diced
- 4 garlic cloves, thinly sliced
- 30 mL (2 tbsp) tomato paste
- 10 mL (2 tsp) ground cinnamon
- 10 mL (2 tsp) dried oregano
- 5 mL (1 tsp) ground allspice
- 2 mL (½ tsp) ground clove
- 3 bay leaves
- 250 mL (1 cup) dry white wine
- 500 mL (2 cups) beef broth
- 750 mL (3 cups) passata
- 15 mL (1 tbsp) granulated sugar
For the Butternut Squash Béchamel:
- 100 g (7 tbsp) unsalted butter
- ¾ cup all-purpose flour
- 1 L (4 cups) whole milk, warmed
- 5 mL (1 tsp) ground nutmeg
- 60 g (½ cup) finely grated Parmigiano-Reggiano, plus more for topping
- 2 large eggs, separated
- 2 cups cooked butternut squash
For Assembly
- 454 g (1 lb) bucatini, cooked just to al dente
- Cooking spray, for greasing
- 1 cup Italian-style breadcrumbs
- Fresh flat-leaf parsley, chopped, for serving
Directions
- Preheat the oven to 350 °F.
- Heat 15 mL (1 tbsp) of oil in a large heavy-bottomed saucepan over medium-high heat. Add the ground lamb and cook, stirring occasionally, until deeply browned. Season with salt and pepper, then transfer to a bowl and set aside.
- Add the remaining 15 mL (1 tbsp) oil along with the onion and garlic. Cook for 2–3 minutes until the onion begins to soften. Stir in the tomato paste, cinnamon, oregano, allspice, clove, and bay leaves, cooking for another 2–3 minutes until fragrant.
- Deglaze with white wine, scraping up any brown bits from the bottom of the pan. Reduce by half, about 3–5 minutes. Add the beef broth, passata, and sugar. Return the reserved browned lamb, bring to a simmer, then reduce heat to low. Simmer gently for 45–60 minutes, or until thick and hearty. Remove from heat and discard bay leaves.
- In a medium saucepan, melt the butter over medium heat. Add the flour and stir with a wooden spoon to form a roux. Cook for 3–4 minutes, until fragrant and lightly golden. Gradually whisk in the warm milk and continue whisking until smooth and thickened, about 3–5 minutes.
- Remove from heat and stir in the nutmeg and grated Parmigiano-Reggiano. Add the cooked butternut squash and purée with an immersion blender until smooth. With the blender running, add the egg yolks and blend to combine. Season with salt and pepper.
- Generously grease a deep 23 × 33 cm (9 × 13 in) baking dish with cooking spray. Scatter the breadcrumbs evenly along the bottom and sides to fully coat.
- Lightly whisk the egg whites and toss them with the cooked bucatini. Spread the pasta evenly in the prepared dish. Spoon the lamb sauce over top, followed by the butternut béchamel. Smooth the surface and finish with a light grating of additional Parmigiano-Reggiano.
- Transfer to the centre of the oven and bake for 45–55 minutes, or until golden brown and bubbling. Let stand for 30 minutes before slicing.
- Garnish with freshly chopped parsley and serve warm.