1. Heat oil in a medium saucepan and saute onion and garlic over medium heat until soft. Add tomatoes, sugar and salt. Bring to the boil, then reduce the heat slightly and simmer for 20 minutes until reduced to about two-thirds of its original volume. The sauce should be quite thick. Taste it and add more salt if required. Remove from the heat and stir through basil.
2. Meanwhile, cut chicken breasts in half horizontally to make two equally thick pieces. Place flour in a shallow bowl and season with salt and pepper, then beat eggs in a second shallow bowl with 1 tblsp water. Put breadcrumbs into a third shallow bowl.
3. Line up flour, egg and breadcrumb bowls in a row. Dip each piece of chicken into flour, then egg, then breadcrumbs, shaking off excess.
4. Heat 5mm oil in a large frying pan or chef’s pan over a medium heat. Fry chicken pieces in batches, don’t overcrowd the pan. Cook for about 3 minutes each side, by which time they will be golden brown and cooked through but still juicy inside. If the heat is too high they will colour too quickly and not be cooked enough in the middle. Use fresh oil after each batch to avoid loose breadcrumbs burning and sticking to the fillets.
5. Preheat a grill to hot and arrange chicken on a baking tray. Spoon tomato sauce over the top, then sprinkle with a generous handful of parmesan cheese. Put the baking tray under the grill for about a minute, or until parmesan starts to turn golden. Serve piping hot with steamed seasonal vegetables or salad or on a bed of soft polenta.