Cauliflower "Mac" and Cheese Casserole

Cauliflower "Mac" and Cheese Casserole
Sea Salt, as needed plus 1/2 tsp
1 large head cauliflower, cut into small florets
1 c heavy cream
1 1/2 tsp spicy brown mustard
1 1/2 c shredded sharp cheddar, plus 1/2 cup for topping the casserole
1/4 tsp ground black pepper 1/8 tsp garlic powder
Equipment: 8 x 8 or 8 x 11 baking dish (may brush a small amount of olive oil if you choose to avoid possible sticking)
Directions: Preheat oven to 375 degrees. Bring a large pot of water to a boil, season the boiling water with sea salt.
Cook the cauliflower in the boiling water until crisp-tender, about 5 minutes. Drain well and pat between several layers of paper towels to dry. Transfer the cauliflower to the baking dish and set aside.
Bring the cream to a simmer in a medium saucepan then whisk in the mustard until smooth. Stir in 1 1/2 cup of cheese, salt, pepper & garlic powder then whisk just until the cheese melts, about 1 to 2 minutes. Remove from heat, pour over the cauliflower and stir to combine. Top with the remaining 1/2 cup cheese and bake until browned and bubbly hot, about 15 minutes.