Chicken parmigiana

4 chicken breasts, sliced through the middle and flattened

150g panko breadcrumbs

100g Parmesan, finely grated

3 eggs beaten

200g flour

100ml olive oil

For the sauce: 

2 tbsp olive oil

3 cloves garlic, crushed

600ml passata

1 onion

1 tsp butter

Salt, pepper, sugar, to taste

For the parmiagana:

2 balls of mozzarella, sliced

Basil or parsley, chopped (optional)