Prep Time: 60 minutes
Preheat the oven to 375 degrees. In a medium sized sauce pan over a medium flame, heat the oil until hot. Add the onion and a pinch of salt and stir until translucent, about 3 minutes. Add the cream along with a pinch of salt and pepper and bring to a simmer. Remove from the heat and set aside.Grease a large casserole dish with a 1/2 Tbsp. butter. Layer in one third of the radish, potato and turnip topped with one third of the butter, followed by one third of the cream and one third of the cheese. Repeat 2 more times. Cover with tin foil and place in the oven for 30 minutes. Remove the foil, rotate and bake for another 20 minutes until golden brown. Divide between 4 plates.