Peel and finely chop the onion. Peel and finely grate or crush the garlic. Halve the chilli and finely chop it, flicking out the seeds and white bits (or leave them in for a hotter sauce). Roughly chop
the tomatoes. Roughly chop the chicken.
Warm 1 tbsp olive oil in a pan over a high heat. Add the chicken. Cook for 5 mins, turning once or twice, till the chicken is browned all over. Lift out of the pan and pop on a plate.
Add the onion to the pan. Turn the heat down to medium. Season with salt and pepper. Cook and stir for 5 mins till the onion is soft and a little golden. Add the garlic and chilli. Cook and stir for 1 min.
Add the chicken back to the pan. Stir in the chopped tomatoes. Pour in 100ml boiling water. Cover and bring to the boil.
When the sauce is boiling, turn the heat down. Simmer for 15-20 mins till the sauce is thick. Stir every so often. If it seems too dry, add a splash more water.
Put a large pan of salted water on to boil. When it’s boiling, add the spaghetti to the pan. Simmer for 8 mins till the pasta is cooked through, tender, but not too soft.
Roughly chop the olives and add them to the puttanesca sauce. Stir to mix. Taste and add more salt and pepper if you think it needs it.
Drain the spaghetti. Add it to the puttanesca sauce. Toss a few times to mix it all together. Serve straight away, garnished with marjoram leaves.