1. Preheat the oven to 180C fan-forced or 200C conventional.
2. Cook the pasta in plenty of salted,boiling water,tipping the cauliflower in for the last five minutes,then drain.
3. While the pasta cooks,add the butter to a medium saucepan and melt over medium heat. Add the garlic and onion,season and cook for four or five minutes,or until softened but not coloured.
4. Add the curry powder and fry quickly. Add the flour and stir through to cook out a little. Pour in the warm milk,whisking as you do. Cook for about two minutes while whisking until the sauce has thickened and is lump-free.
5. Add the cream and half the cheese,whisk until combined and season. Tip into a large bowl with the tuna and the pasta and cauliflower. Stir through,breaking up the larger pieces of cauliflower a little.
6. Tip the pasta mix into a ceramic baking dish,top with the rest of the cheese and the breadcrumbs and bake for 20-30 minutes or until golden.