Cheesy Roasted Cauliflower

Ingredients

• nonstick cooking spray
For Cauliflower:
• large head cauliflower
• 1 1/2 tbsp. extra virgin olive oil
• 1/2 tsp. salt
• 1/4 tsp. pepper
For Cheese Sauce:
• 1/4 tsp. pepper
• 4 tbsp. unsalted butter
• 2 large cloves garlic, minced
• 4 tbsp. flour
• 2 cups milk
• 2 cups shredded sharp cheddar cheese, divided
• salt and pepper, to taste
For Topping:
• 1/2 cup panko
• 1/2 tbsp. extra virgin olive oil
• 1/2 tsp. salt
• 1/8 tsp. pepper
• 1 tbsp. chopped flat leaf parsley

Instructions

1. Preheat oven to 425 degrees. Spray a large baking sheet with nonstick cooking spray.
Prepare cauliflower:
2. Cut cauliflower into large florets and place on baking sheet.
3. Drizzle cauliflower with 1 1/2 tbsp. olive oil, then sprinkle with 1/2 tsp. salt and 1/4 tsp. pepper. Mix well.
4. Place baking sheet in oven and roast cauliflower until tender, about 15 minutes.
Prepare cheese sauce:
5. While cauliflower is roasting, melt butter in a medium skillet over medium high heat.
6. Add garlic to butter and saute until fragrant, about 30 seconds.
7. Stir flour into butter with a whisk.
8. Continue cooking, stirring constantly, until flour mixture is golden, about 2-3 minutes.
9. Slowly whisk in 2 cups milk.
10. Cook, stirring frequently, until sauce is thickened, about 2-3 minutes.
11. Stir 1 1/2 cups cheddar cheese into sauce until smooth. (Reserve remaining cheese for assembling gratin.)
12. Remove cheese sauce from heat, then season generously to taste with salt and pepper.
Prepare topping:
13. Place panko in a small bowl.
14. Drizzle with olive oil, then add salt and pepper. 
15. Stir together well. 
Assemble gratin:
16. Spray a shallow casserole dish with nonstick cooking spray.
17. Add roasted cauliflower to casserole.
18. Pour cheese sauce evenly over cauliflower.
19. Sprinkle remaining 1/2 cup cheese over sauce.
20. Top gratin with panko.
21. Place gratin in oven and bake for until browned and bubbly, about 25 minutes.
22. Let gratin cool for a few minutes, sprinkle with parsley, and serve. Enjoy!

Source: http://hellolittlehome.com/cheesy-roasted-cauliflower-gratin/