1. Preheat oven to 200C. Heat a large heavy based saucepan over medium heat, add olive oil, bacon and leek and cook for 5 minutes. Add garlic and 3 tbsp thyme and cook for a further 2 minutes.
  2. Add butter, allow to melt, then stir through flour, cooking for 3 minutes.
  3. Slowly add the milk, whisking continuously, bring to the boil then simmer for 10 minutes, stirring occasionally.
  4. Add cream, mustard, cheddar and gouda and heat gently to melt the cheese. Season to taste with salt and pepper.
  5. Meanwhile, in a pot of boiling salted water, add the pasta and cook as per packet instructions.
  6. Place pasta into the sauce, stir well to incorporate and pour into a baking dish. Mix together the parmesan, breadcrumbs and remaining thyme in a small bowl.
  7. Top the pasta with the mozzarella followed by the breadcrumb mix.
  8. Bake for 20 minutes or until the breadcrumbs are golden and crunchy.
  9. Allow to rest for 5 minutes before serving.
  10. Enjoy with family and friends!