Preheat oven to 350F. Combine the butter, dill, lemon zest, garlic, cumin, salt and pepper in a small bowl. Blend well. Trim the leaves off the cauliflower and trim the stem so that it is flush with the bottom of the head. The aim is to allow it to sit steadily. Slather the butter mixture over the top and sides of the cauliflower. Place in an oven-safe dish and cover tightly with foil. Bake until tender, about 1-1/4 hours. Transfer the cauliflower to a heated platter, spoon the pan juices over it and bring to the table whole.