We're buttering up your usual mac and cheese with sweet and soft butternut pumpkin. This veg addition to the classic takes the guilty edge off treat night so you can really enjoy that deep and comforting cheesiness. Best of all, it's cooked in one pan with a final turn under the grill to get that golden and molten top, just as you like it.
Preheat overhead oven grill to high. Cut green top from leek and discard. Halve leek lengthwise, rinse under cold water and thinly slice. Peel and crush garlic. Zest lemon. Peel pumpkin and chop into 2cm cubes. Remove rosemary leaves from stems and roughly chop.
Melt butter in a frypan over medium heat. Add leek and rosemary, season with ¼ teaspoon salt flakes and pepper and cook, stirring occasionally, for 5–6 minutes or until leek is golden.
Add garlic, lemon zest and pumpkin and cook, covered with a lid and stirring occasionally, for a further 7–8 minutes or until pumpkin is starting to soften.
Dissolve stock cube in 500ml (2 cups) boiling water. Add macaroni, stock and milk to pan and bring to a simmer. Cover with a lid and reduce heat to medium-low. Cook, stirring occasionally, for 8–10 minutes or until pasta is tender and most of the liquid has been absorbed. Remove from heat and season to taste with salt and pepper.
Spoon bechamel sauce on top of pasta and sprinkle with mozzarella. Place under preheated grill for 6–8 minutes or until golden brown and bubbling.
Allow pasta to sit for 5 minutes before serving. Cut lemon into wedges. Toss salad leaves with your favourite dressing. Divide pasta between bowls and serve with salad and lemon.