Kale Madeline

0 Preheat the oven to 375°F.
1 Cook the frozen kale in the microwave in a microwave-safe dish. When cooked through, let cool and then drain in a fine mesh strainer over a bowl and save the liquid.
2 In a skillet, melt the butter and add the flour, forming a blonde roux.
3 Add the onion, cooking until translucent and coated in the roux.
4 Pour in the milk, Worcestershire and the reserved kale liquid. Season with the celery salt, as well as freshly ground black pepper and salt.
5 Simmer until the sauce has thickened substantially, then add in the kale and [adjustable]¾ cup[/adjustable] of the cheese, stirring until combined.
6 Pour into a greased baking dish, top with the remaining [adjustable]¼ cup[/adjustable] of cheese, and transfer to the oven.
7 Bake for 20-30 minutes, or until the cheese on top is brown and bubbly.
8 Serve warm and enjoy!