Divide the lettuce over the plates.
Finely chop the red onion and place the pieces in a bowl with honey and raspberry vinegar. Mash in the raspberries, but keep a few aside for garnish.
Season the livers and let the butter foam in a frying pan. Fry until nicely colored and crispy on both sides. This takes about 5 minutes. Don't overcrowd the pan; do it in two batches if necessary so they can fry nicely, and definitely do not let them boil.
Distribute the livers over the lettuce. Pour off the fat and deglaze the pan with raspberry vinegar and mashed raspberries.
Season with pepper and salt and stir in the oil.
Divide onto the plates and finish with coarsely chopped pistachios and raspberries.