Chicken pasta bake

Ingredients:

4 tbsp olive oil
1 onion, finely chopped
2 garlic cloves, crushed
¼ tsp chilli flakes
2 x 400g cans chopped tomatoes
1 tsp caster sugar
6 tbsp mascarpone
4 skinless chicken breasts, sliced into strips
300g penne
70g mature cheddar, grated
50g grated mozzarella
½ small bunch of parsley, finely chopped