Fill a pot with water and 2 teaspoons of salt, and bring it to boil. Add cauliflower florets and boil for 5 minutes, until they are soft but still yielding a crunch. Drain and transfer to a large mixing bowl.
Meanwhile, add olive oil and leeks in a pan over medium heat and cook until leeks are tender. Add them to the mixing bowl.
In a bowl, whisk cream cheese, sour cream, and miso paste until smooth. Stir in garlic powder and season well with salt and pepper.
Pour the mixture over the cauliflower and leeks and mix with a spatula until the vegetables are evenly coated.
Spread the cauliflower mixture into the casserole dish and top with cheddar cheese. Bake in the oven for 20-25 minutes, until the cauliflower is tender and cheese, melted.
Take the casserole out of the oven and top with scallions and bacon bits. Serve.
Store any leftovers covered in the fridge for 2-3 days.
Keywords: Thanksgiving, Christmas, comfort food, winter food, side dish