Method

Preheat the oven to 190C/374F/gas mark 5. Cook the pasta according to the packets instructions, then drain and set to one side. In a large saucepan heat the olive oil and fry the bacon pieces until crispy, then drain on some kitchen roll. Remove the fat from the pan then add the butter. Allow to melt then stir in the flour. Cook for 2 minutes before slowly whisking in the milk and stock. Use a whisk to prevent lumps from forming. When all the liquid has been added, bring to the boil then stir in the cooked bacon and 3/4 of the cheese. Add a little more stock or milk if the sauce is thick as it will thicken when it is in the oven. Stir well before mixing the sauce with the pasta. Place the pasta into an oven proof dish. Cover the top with the sliced tomatoes before sprinkling with the remaining cheese. Place in the oven for 20-30 minutes until golden brown and serve straight away.