Preheat oven to 200°C.
Lightly grease a shallow ovenproof dish.
Toss chicken in KNORR Classic White Sauce, shaking off excess.
Dip in egg and coat in combined breadcrumbs and herbs.
Fry in oil on a medium heat.
Cook chicken in batches for 1-2 minutes each side, until browned.
Pour one tin of tomato & onion mix over the bottom of the dish and top with half of chicken, and half the mozzarella.
Repeat layers and season.
Bake for 30 minutes, until bubbling and cheese is golden.
Serve with green salad.