Preheat oven to 400F/200 C and spray a medium-sized baking dish with non-stick spray. (This dish splatters a bit when it's baking so a baking dish with high sides will be the best.)
Peel the turnips and cut into half inch slices, then pile up the slices and cut into fourths.
Cut thick-sliced bacon into squares and brown well in a large frying pan (big enough to hold all the turnips).
Remove bacon to paper towels to drain and leave about 1 T of bacon grease in the pan, or use olive oil if you prefer.
Add turnips and dried thyme and cook 5-6 minutes, or until turnips are barely starting to soften.
Add bacon and cook 1-2 minutes more.
Then add heavy cream and both types of grated cheese and stir to combine.
Transfer to the baking dish and bake 35-40 minutes, or until turnips are soft when you stick a fork into one of them and the top is nicely browned.
Serve hot and enjoy!
