1 large head cauliflower, cut into bite-size florets
Kosher salt, to taste
2 tablespoons unsalted butter
2 tablespoons all-purpose flour
2 cups whole milk
1 tablespoon fresh thyme, finely chopped, plus more for garnish
4 ounces cream cheese, room temperature
3/4 cup sharp white cheddar, shredded, divided
Freshly ground black pepper, to taste
1/4 cup parmesan cheese
01Preheat oven to 400 F. Lightly coat medium casserole dish with butter. Cut top off garlic head, exposing tops of cloves and set into square of aluminum foil. Drizzle 1 tablespoon olive oil over garlic head and wrap tightly with foil. Roast in oven until tender, 30-40 minutes. Remove from oven, unwrap foil and let cool. Roasted garlic can be made 3 days head and stored covered in refrigerator.
02Meanwhile, toss cauliflower florets in remaining olive oil and season with salt. Spread onto rimmed baking sheet and roast cauliflower alongside garlic in oven for 15-20 minutes, until golden. Transfer to prepared baking dish.
03Melt butter in medium saucepan over medium heat. Squeeze out about half of roasted garlic cloves into butter and mash with spoon to break up. Sprinkle flour over butter and stir to combine. Cook 1 minute until golden brown, then slowly whisk in milk. Reduce heat to medium-low and continue to whisk until thickened, 3-5 minutes.
04When sauce is thick enough to coat spoon, remove from heat and whisk in thyme, cream cheese and 1/2 cup cheddar until smooth. Season with salt and pepper to taste.
05Pour cream sauce over cauliflower in baking dish and sprinkle with remaining cheddar and parmesan. Bake, uncovered until cheese is golden brown and bubbling, 15-20 minutes. Garnish with thyme and serve warm.