1. Preheat the oven to 350°F.

2. Trim, halve, and wash the leek. Peel the garlic. Then, finely slice the broccolini stalks (reserving the florets for later). Place all in a large casserole pan over a medium heat with the butter.

3. Strip in the thyme leaves and add to the pan and cook for 15 minutes, or until sortened, stirring regularly. Stir on the flour, followed slowly by the milk, then simmer for 10 minutes, or until thickened into a sauce, stirring regularly.

4. Meanwhile, cook the pasta in a large pan of boiling salted water for 5 minutes, then drain. Grate the Parmesan and most of the cheddar into the sauce and mix well.

5. Add sauce into a blender, add the spinach, and blend until smooth – you may need to work in batches. Season to taste with sea salt and black pepper, then stir sauce into the pasta and broccolini florets, loosening with a splash of milk, if needed.

6. Transfer to a 14x10-inch baking dish. Grate over the remaining cheddar and top with almonds. Bake for 30 minutes, or until beautifully golden and bubbly.