Cheesy Cauliflower Casserole

Ingredients

• 1 large yellow onion
• 6 tablespoons butter
• 1 tablespoon olive oil
• 1/2 teaspoon dried thyme
• 1 medium head cauliflower (about 1.5 or 2 lbs)
• 1 tablespoon salt
• 2-3 cloves garlic
• 4 tablespoons flour
• 3 cups whole milk
• 1/2 teaspoon mustard powder
• 1/2 teaspoon salt
• 1/4 teaspoon smoked paprika
• 1/8 teaspoon freshly ground nutmeg
• a pinch of cayenne pepper
• 1/4 teaspoon black pepper
• Yukon gold or russet potatoes
• 2 and 1/2 cups sharp cheddar cheese
• 2 tablespoons cream cheese
• parsley

Method

1. Cut the onion into even slices.
2. Melt 2 tablespoons of butter and 1 tablespoon of olive oil over medium low heat and toss in the onions.
3. Sprinkle in half a teaspoon of dried thyme and let the onions cook slowly until golden brown and jammy, stirring occasionally.
4. Cut the cauliflower into large florets.
5. Add 1 tablespoon of salt to boiling water, then drop in the cauliflower florets and let them cook for about 3 minutes.
6. Transfer the florets to a bowl of iced water for 2 minutes to stop the cooking.
7. Pat the florets dry with a clean towel or paper towel.
8. Dice 2-3 cloves of garlic.
9. In the same saucepan, melt the remaining 4 tablespoons of butter over medium heat and toss in the garlic for about 30 seconds until fragrant.
10. Sprinkle in 4 tablespoons of flour and whisk for about 1 minute until lightly golden.
11. Gradually whisk in 3 cups of whole milk, adding it in small splashes while stirring continuously.
12. Bring the sauce to a gentle boil, reduce the heat, and season with mustard powder, salt, smoked paprika, nutmeg, cayenne pepper, and black pepper.
13. Set the sauce aside to cool slightly.
14. Slice Yukon gold or russet potatoes into thin slices.
15. Grate 2 and 1/2 cups of sharp cheddar cheese and melt it into the sauce along with 2 tablespoons of cream cheese.
16. Mix in the fried onions to the cheese sauce.
17. Grease a 9 by 13 inch baking dish with olive oil and layer the potato slices in a single overlapping layer.
18. Pour half of the sauce over the potatoes, spreading it evenly.
19. Layer in the cauliflower florets and pour the rest of the sauce over the casserole.
20. Top with yellow cheddar cheese.
21. Cover with foil and bake in a preheated oven at 375° F for 35 minutes.
22. Uncover and bake for another 25-30 minutes, and for extra browning, broil for 1-2 minutes.
23. Mince some parsley and let the casserole rest for at least 10 minutes before serving.