Celeriac, Butternut Squash, and Marscarpone Parmigiana
- Preheat the oven to 180C/gas 4 and bring a pan of slightly salted water to the boil.
- Drop the chopped onion into the boiling water. When it comes back to the boil, drain and set aside the onions.
- In the same pan, put the marscarpone, cream, sage leaves, garlic, Parmesan rind (in one chunk) and chilli flakes. Season heavily as it starts to bubble, then turn the heat right down so that it's just steaming while you prepare everything else.
- Peel and halve the celeriac and butternut squash and slice them into 3mm-thick discs.
- Take the rind out of the infused cream and discard. Whizz the cream with a blender until smooth. Grate the remaining Parmesan and the fontina in a bowl and mix well.
- Choose an ovenproof dish big enough to hold all the ingredients and grease it with butter.
- Layer it up. In between each layer of root veg, sprinkle some cheese and blanched onion and spread some of the thick, infused cream. The top layer should be just onions and cheese. Cover with foil or a lid.
- Cook for 40 minutes-1 hour until a knife can be poked through the veg with relatively little resistance. Remove the lid or foil, crank the heat up to 200C/gas 6 and give it another 10 minutes or so until the top has gratinated nicely.