Preheat the oven to 450°F (235°C) and line a baking pan with baking paper.
In a large mixing bowl, combine the cauliflower florets with olive oil, a pinch of sea salt, and pepper. Mix to coat well.
Arrange the florets on the prepared baking pan and roast for 15-20 minutes until slightly golden.
Heat the cheddar cheese with the heavy cream, almond milk, and butter in a medium-sized saucepan, stirring to create a smooth cream.
Remove from the heat and add the cauliflower into the saucepan. Fold carefully to coat the cauliflower with the cheese sauce—season with a pinch of nutmeg.