Preheat the oven to 400°F. Lightly grease the bottom of a Dutch oven or baking dish.
Remove the outer leaves from the cauliflower. Cut the stem flat so the cauliflower can sit upright in the pan (make sure not to cut too much to prevent the cauliflower from falling apart).
1 head cauliflower
In a small bowl, combine the melted butter, olive oil, minced garlic, lemon zest, parsley, 2 tablespoons parmesan cheese, Italian seasoning, salt, and pepper. Stir well to combine.
Rub 3/4 of the butter mixture over the entire head of cauliflower, making sure to include the sides.
Place the cauliflower in the prepared pan and cover with a lid or aluminum foil. Bake for 40-45 minutes. Remove the lid and baste with the remaining butter mixture (you might need to briefly heat it in the microwave to re-melt the butter). Sprinkle with the remaining parmesan, then roast for an additional 15-20 minutes, uncovered, until the exterior is golden brown. For an even crispier exterior, broil during the final 3-5 minutes.
1 tablespoons freshly grated parmesan cheese
Let the cauliflower cool for 5 minutes, then slice into thick slices or wedges. Garnish with fresh parsley.
Prepare the sauce
Prepare the sauce while the cauliflower is roasting. Heat 1 tablespoon olive oil in a skillet set over medium heat. Add the garlic and cook, stirring, until soft and fragrant, 1-2 minutes. Remove from the heat and cool for 2-3 minutes.
1 tablespoon extra virgin olive oil, 1/4 cup garlic cloves
Transfer the garlic to a food processor along with the lemon juice, salt, pepper, and remaining olive oil. Puree until smooth.
2 tablespoons fresh lemon juice, 1/2 teaspoon fine sea salt, 1/4 teaspoon ground black pepper, 1/2 cup extra virgin olive oil
Serve drizzled over or alongside the roasted cauliflower.
Notes
Make sure the olive oil used in the sauce isn’t overly bitter or peppery. If it has a strong flavor, consider substituting it with a neutral-flavored oil such as avocado.