Clean the chicken livers cut away any sinew, blood or green bits, then set enough aside to run along the length of your terrine dish or loaf tin. Chop the rest into small cubes. Tip all the ingredients except the prosciutto, whole livers and cornichons, etc, to serve into a large bowl. Season and mix well with your hands. If you have time, you can cover and set aside in the fridge for the flavours to mingle for a few hours or overnight.
Line the base and sides of a 1kg terrine dish or small loaf tin with baking parchment. Then carefully line the base and sides of the dish/tin with the overlapping slices of prosciutto (A), leaving some hanging over the side and a few slices for the top. Pack half the meat mixture down into the terrine and press down.
Lay a row of chicken livers down the middle of the terrine (B), then add the rest of the meat mixture and press down.
Lay the remaining prosciutto over the top, then lift the slices from the sides up and over, and cover the dish with foil.
Heat oven to 180C/160C fan/gas
If you have a spare cardboard box in your kitchen, cut a piece of card out slightly larger than the base of the terrine. Put it in a deep roasting tray and sit the terrine on top (this helps the terrine to cook evenly). Boil a kettle and pour in enough water so it comes halfway up the terrine. Carefully place it on the middle shelf of the oven and cook for 1 hr.
Remove the tin from the oven, take out the terrine and leave to cool completely.
Place on a plate or a tray with another flat tray on top, weigh down with a few cans and leave to chill overnight. To turn out the terrine, slip a knife between the paper and the terrine to loosen it, then turn it out onto a board. Wipe off the jelly and either serve straight away sliced or wrap in cling film and slice later.
Serve with toasted bread a favourite of mine is walnut bread and some nice leaves dressed with walnut oil. You can keep the terrine for up to two days, but it will start to lose its colour.
