To make the breadcrumb topping, roughly chop the bread so that you have smaller and larger pieces.
Take a frying pan and add the olive oil, garlic cloves (whole with the skin on) and thyme.
Fry the garlic and thyme for 2 minutes on a medium heat to flavour the oil then add the breadcrumbs.
Season with salt and pepper and cook for 3-4 minutes or until golden brown. Remove from the pan and set aside.
Finely slice the onion and cut the leek into approximately 1cm rounds.
Add 1 tbsp of olive oil to a pan and add the onion and leek and season generously with salt and pepper.
Cook on a high heat for 2 minutes.
Finely chop the garlic and add along with the thyme.
Turn down to low and cook for approximately half an hour until the onion and leek become sticky and soft.
Cook the pasta according to packet instructions, grate the cheese and add both to the leeks.
Mix well and serve with some of the breadcrumbs sprinkled on the top.