Preheat the oven to 370 degrees f. Line a baking sheet with foil or parchment paper.

In a large bowl, toss together the cauliflower florets with half of the melted butter. Season with a bit of sea salt and black pepper.

Arrange the cauliflower florets on the prepared baking sheet in a single layer. Roast for about 10-15 minutes, until crisp-tender.

In a small saucepan, over low heat, add the cheddar cheese, milk, and remaining butter, stirring constantly.

In a small bowl, add the flour and 2 Tbsp of water and mix until smooth.

Add this mixture to the cheese sauce and whisk well to

combine, then simmer for a couple of minutes to thicken. Be careful not to burn the cheese. Taste and season with sea salt if needed.

Toss cauliflower with cheese sauce right before serving, then sprinkle with crispy bacon crumbles.