Ingredients

• 220g streaky bacon (or leftover ham if you have some, chopped into pieces)
• 1 x large leeks, chopped
• 1 x 25 g butter for the leeks and 1 x 50g butter for sauce
• 2 x heaped tbsp plain flour
• 150 g grated medium strength white cheddar cheese
• 800ml milk
• 350g dried pasta (fusilli, penne or whatever needs using up)
• 200g grated cheese

Instructions

Prepare leeks and bacon

1. Start by boiling a pan of water and then cook the pasta for 10 minutes. Remove from the heat, sieve and run under the cold tap to stop it cooking further. Then set it aside in the baking dish.
2. At the same time fry the bacon until the majority of fat has rendered and it is crispy (or cook it in the air-fryer until crispy). Then put it aside on a plate until cool, and chop into small 1cm size pieces and place in the baking dish.
3. Before chopping the leeks make sure you have cleaned them properly by running a knife lengthways and running them under a cold tap to get rid of any dirt that may be inside them. Then chop them laterally into 1cm thick pieces. I use the leek up to about halfway up from the transition from white to green, so there is a mix of white and green.
4. Next, melt 25g of butter in a pan and use it to sweat the leeks on a low heat until they are soft. Do not burn them. When done, add to the pasta and bacon.

Make the sauce

1. At the same time make the white sauce: melt the 50g piece of butter in a saucepan and add the garlic and cook for 1 minute. Then add the flour and mix together and cook for another minute. 
2. Then slowly add the milk bit by bit, whisking with a hand whisk to get rid of any lumps. Cook until it starts to get thick, then add the cheddar cheese to the sauce, stirring all the time.

3. Then mix all the contents of the baking dish and add the sauce to the contents and stir properly to make sure the sauce settles to the bottom and covers the pasta. 
4. Then cover the top with grated cheese put in the oven for around 15mins.