Method: 

STEP 1:  Pre-heat the oven to 180°C. In a saucepan on a low heat put the cream, halve the bulb of garlic and place it into the cream along with the herbs and a generous amount of salt and pepper. Let this infuse for about 10 minutes. Keep an eye on it to make sure the cream doesn't boil over.

STEP 2: Using a mandolin on medium thickness slice the peeled squash, celariac and parsnips. (If you don't have a mandolin you can use a knife, just try and slice the veg the same thickness so it cooks evenly.) Layer them into a baking dish making sure that every layer has a relatively even amount of all the veg. Every few layers take a some of the cream mix and pour it onto the veg. (Try to avoid getting the herbs and garlic in there.) 

STEP 3: Once you have layered all the veg and used up all the cream, spread the grated cheeses across the top. Cover with a layer of greaseproof and then a layer of foil. (The greaseproof will stop the cheese sticking to the foil). Place it into the oven and roast for 45 minutes. 

STEP 4: After 45 minutes, take it out of the oven and remove the foil and greaseproof. Return to the oven and continue cooking to get some nice colour on the cheese and crisp up the edges. This should take about 10-15 minutes. Once golden and bubbling it is ready to serve.