Clean a full head of cauliflower (white, orange, green, or purple). Cut an X across the top of the head, about 2 inches deep. Spread the aioli on top, making sure to work it into the X and the crevices of the cauliflower. Steam cauliflower until tender. Remove from steamer and place on a cookie sheet. Cover top of the cauliflower with grated Cheddar cheese. Make sure cheese goes into X cuts. Place under broiler until cheese is melted and charred. Remove cauliflower from broiler and cut in quarters, using X as a guide.