Preheat your oven to a cozy 450°F (232°C).
In a large mixing bowl, gently toss your cauliflower florets with the melted butter (or oil), a sprinkle of sea salt, and black pepper. Spread them out in a small 1.5-quart casserole dish. Pop it in the oven and roast for about 25-30 minutes, giving it a stir halfway through, until the cauliflower is wonderfully tender and lightly browned.
While the cauliflower is roasting, give the same bowl a quick wipe. Whisk together the sour cream and heavy cream until it’s smooth and creamy. Stir in the minced garlic, half of your shredded cheddar cheese, half of the crispy bacon bits, and half of the chopped green onions. Taste and add a little more salt and pepper if you like, but remember, the cheese will add more saltiness later!
Once your roasted cauliflower is ready, carefully add it to the bowl with your creamy sauce. Stir it gently until all the florets are coated in that delicious goodness. Return this mixture to your casserole dish.
Sprinkle the remaining cheddar cheese and bacon over the top. Slide it back into the oven for just 5-10 minutes, or until the cheese is beautifully melted and bubbly.
Garnish with the rest of the fresh green onions, and get ready to dig into this comforting, healthy dish!