Just like potato dauphinois, but with a twist! This is also very creamy and tender but turnip requires different herbs and spices, so I've added fresh thyme and nutmeg.
Place the onions in a frying pan.
Heat oven to 175C/160C fan/gas 4 and grease a shallow baking dish.
Fry the onions until they are golden brown and crispy.
Slice the turnips and add them to the baling dish. Cover the first layer with the fried onions and thyme.
Add half of the cheese.
Add another layer of turnip, pour the single cream on the top of it evenly and sprinkle with the remaining cheese.
Pop it into the oven for about 80 minutes - the turnips cook slowly! I never cover it as I don't use foil so it takes about this much. After about an hour in the oven, check them with a fork.
Serve it immedately.