Cook the cauliflower and broccoli until tender. Drain and place in an overproof dish with the cooked pasta.
Meanwhile, heat the white sauce, add 400g Cheddar cheese and the Schwartz for Chef Mesquite Seasoning and heat through. Pour over the cauliflower, broccoli and pasta mixture.
Top with the remaining cheese and bake in a pre-heated oven at 190ºC, 375ºF, Gas Mark 5 for 20 minutes until golden.