Peel and roughly chop the shallot, and peel and finely slice the garlic.
Trim away any sinew from the chicken liver and heart, and roughly chop the bacon.
Place the bacon in a small non-stick frying pan over medium-high heat and fry for five minutes, then add the butter, shallots and garlic, and cook for another five minutes, or until softened.
Add the liver and heart and colour all over, then pour over the Calvados. Carefully tilt the pan to catch the flame (or light with a long match) and let it flambé – stand back! When the flames subside, tip it all onto a board and finely chop into a coarse pâté.
Slice the cornichons in half lengthways and place in a bowl, then pick in the parsley leaves, and add a splash of white wine vinegar.
Toast the baguette slices on a griddle over high heat, then drizzle with extra virgin olive oil. Spread over the pâté and top with the cornichons.