Step 1
Preheat the oven grill to high and lightly grease a baking tray.
Step 2
Heat the oil in a large deep-sided frying pan over medium heat. Add the garlic and leek and cook, stirring occasionally, for 4 minutes or until fragrant. Remove with a slotted spoon and set aside.
Step 3
Add the mascarpone and goat’s cheese to the pan and stir to melt, then add the provolone and parmesan and stir to melt. Take off the heat and keep the sauce warm.
Step 4
Meanwhile, cook pasta in salted boiling water for 6–8 minutes, or until al dente. Drain the pasta, reserving ½ cup of the cooking water. Return the pasta and the reserved cooking water and leeks to the cheese sauce and stir to combine.
Step 5
Transfer the pasta to the baking tray. Place under the grill for 6–8 minutes, or until golden and crisp around the edges. Grate over the nutmeg, scatter with chervil, if using, and serve.
