In a large bowl, whisk the eggs together with the milk, salt and pepper, grated cheddar cheese and the cream cheese.
Add into the egg mixture the bread cut or broken into chunks. Mix well and set aside but remember to stir in occasionally so that the bread soaks well. It is best to keep in the fridge but do not forget to pay a mixing visit and stir it from time to time. Allow it to soak for at least 30 min.
Meanwhile, place a pan on medium heat and slightly cook ¾ of the pancetta and the chopped onion. Cook until these get slightly brown. Remove the pancetta and the onion from the heat and set aside.
Heat the oven to 180°C or 350°F.
Spray or grease a 20-21 cm cake tin. When the egg and bread mix is ready, take out of the fridge and pour into the greased/sprayed oven dish. Spread evenly the mixture and scatter the ¼ pancetta left aside.
Bake for 30 minutes until nice and golden brown on top.
Serve warm or cold with some parsley sprinkled over. Enjoy!