Fill your kettle and boil it, then fill a large pan with the hot water, topping it up if needed. Add a pinch of salt, pop on a lid and set on a high heat to come back to the boil.

Meanwhile, peel the onion and finely chop it. Halve the chilli, flicking out the seeds and white pith for less heat, and finely chop the chilli.

Pour 1 tbsp olive oil into a medium pan and set it on a medium-high heat. Add the chicken pieces and season with salt and pepper. Fry for 3-4 mins, turning halfway, till golden brown.

Add onion into the pan with the chicken. Cook, stirring, for 4 mins till softened. Stir in the chilli and cook for 1 min. Pour the chopped tomatoes into the pan and add 1 tsp caster sugar. Bring to the boil, then reduce to a simmer. Partially cover the pan with a lid and cook for 10 mins, stirring every now and then.

Meanwhile, check the pan of water. When it's boiling, add the spaghetti. Cook for 8 mins, till tender with a slight bite, then drain.

Taste the arrabiata sauce and add a pinch more salt or pepper if you think it needs it. Add the spaghetti and toss to mix. Divide the spaghetti and chicken arrabiata between 2 warm plates or bowls and garnish with parsley leaves to serve.