Turn your oven to 375. Prepare your pie crust by allowing to come to room temp and then prick all over with fork. Pre-bake for 10 minutes.
Remove center rib from kale and tear leaves into bite-sized pieces. In a deep skillet or pot, wilt the kale with a splash of water over medium heat.
Finely chop your bacon and begin to brown it in another skillet or pot. Once it's almost cooked, add the onions and stir them into the grease to soften.
Using a slotted spoon, remove onions and bacon and add to the kale. Reduce the heat under the drippings to very low and whisk in flour, and whisk continuously for at least a minute. Slowly pour in the milk/cream/stock while still whisking to make your roux. Stir till it's thick enough to coat the whisk. Stir in a half tsp salt, a quarter tsp of pepper and some very finely grated cheese.
Pour the roux into the skillet with the kale, bacon and onions and stir well. It'll look like a mess but it's going to be delicious.
Pile it all into your pie crust and bake for 15 minutes and an additional 2-3 under the broiler. Allow to cool for 5 minutes, then slice and serve.