I know these days the poultry police say you should cook your livers all the way through ... By all means use store-bought caramelised onions, as there is a bunch of pretty good ones on the ...
Sauté until the onion is soft and translucent, then add the chicken livers and spices. Turn up the heat and fry until the livers are just cooked through, this should take about 3-5 minutes.