Trim and dice the courgettes. Peel and grate or crush the garlic. Roughly chop the tomatoes.
Warm 1 tbsp olive oil in a deep frying pan or wok. Add the lardons. Stir and fry over a medium heat for 5-6 mins till the lardons are golden and crisp. Lift them out of the pan. Pop on a plate lined with kitchen paper.
Add the courgettes to the pan. Stir and fry for 5 mins till they’re golden. If they seem a bit dry and are sticking, add a splash of water.
Stir in the garlic. Cook for 1 min till the pan smells sweet. Stir in the tomatoes. Add a pinch or two of dried chilli flakes (they're spicy so use as much as you prefer) and ½ tsp sugar. Add the lardons back to the pan.
Season the sauce with a little pinch of salt and a big pinch of pepper. Warm till it starts to simmer. Turn the heat down. Cook without the lid for 10-15 mins till the sauce looks thick and rich.
While the sauce cooks, fill a large pan with boiling water. Add a pinch of salt. Cover. Bring to the boil. Add the penne. Simmer for around 8 mins till the pasta is cooked but still has a bite.
Taste the sauce. Season or add more sugar and dried chilli flakes if it needs it. Drain the penne. Serve the penne with the Amatriciana sauce, garnished with parsley leaves.