Preheat oven to 280 degrees C (550 F), or the highest setting. Adjust oven rack to the upper level, so a baking sheet will be 2-inch below the broiler.
Separate cauliflower into bite size florets and place onto a large baking sheet. (Read blog post above to see how to cut cauliflower easily) Toss with 4 tablespoons olive oil, sea salt, and black pepper.
When oven is preheated, turn on broiler. Broil cauliflower until the top side is browned, 7 to 8 minutes. Flip and roast until the other side is browned, 3 to 4 minutes. You should set a timer for every 2 to 3 minutes, and keep an eye on the cauliflower during the cooking to prevent from burning.
Heat the homemade orange sauce in microwave for 1 minute or until hot, but not bubbling.
Remove the cauliflower from the oven. Pour sauce over the cauliflower and toss to coat well.
Garnish with nuts, chopped parsley, and serve with hot sauce, if using.
Notes
Read the blog post above to see details of how to roast frozen cauliflower.