In a small bowl, combine the softened butter, minced garlic, thyme, dill, lemon zest, salt and pepper until it forms a paste. Use a pastry brush and coat the entire cauliflower.
Place the head of cauliflower into a crockpot and pour the broth into the bottom. (could add 2 tbsp lemon juice and zest in there too if you want a citrus kick) Turn the crockpot on high and let it cook 3 ½- 4 hours, until tender.
Remove and slice to serve, topping with fresh parmesan and parsley and broth from the base of the slow cooker.