Whisk milk, olive oil and egg. Add in flour, salt and black pepper and whisk until smooth. Fold in 3/4 of parmesan. Toss in the steamed cauliflower florets and coat them well with this sauce. Transfer it into a casserole dish and bake for 40 minutes. Remove the casserole from the oven, throw the remaining Parmesan over it and bake for another 5 minutes or until the cheese melts and gets golden.