Preheat oven to 180°C/160°C fan-forced. Cook the pasta following packet directions

Meanwhile, heat oil in a large frying pan over a medium-high heat. Add onion, garlic and bacon. Cook, stirring often, for 3-4 minutes until onion softens. Add zucchini and carrot. Cook, stirring often, for 3 minutes until vegetables begin to soften. Stir in mushrooms and tomatoes. Cook, stirring occasionally, for 2 minutes. Add mushroom mixture to pasta. Set aside

To make cheese sauce, melt butter in a medium saucepan over medium heat. Add flour. Stir until bubbling. Remove from heat and gradually whisk in milk. Return to heat, bring to the boil, stirring over medium heat until thick and smooth. Reduce heat and stir in cheese until smooth. Season. Remove from heat

Add half the cheese sauce to the pasta mixture. Stir to combine. Spoon pasta mixture into a 12-cup capacity greased baking dish. Pour over remaining cheese sauce. Smooth top and evenly sprinkle with cheese blend. Bake for 40-45 minutes or until golden and bubbling. Serve