To cook chicken livers, sauté sliced onions in chicken fat, season and brown 1 pound chicken livers, chop the livers and onions, and mix them with crumbled eggs and seasonings. Chill the dish in the refrigerator until serving time.
Rinse and dry 1 pound of chicken livers. Use a small knife to remove the fat and membranes. Distribute the livers evenly on a baking sheet, and sprinkle them with salt and pepper. Peel and slice a large onion. Heat 2 tablespoons chicken fat in a pan over medium heat, add the onions, and cook them until they soften and darken.
Transfer the onions to a plate, wipe out the pan with a paper towel, and return it to the burner. Add 2 tablespoons chicken fat, and then put a single layer of chicken livers in the hot fat. Cook them for about two minutes per side, flipping them with kitchen tongs when one side is brown. Put the cooked livers on top of the reserved onions, add more fat to the pan, and brown the remaining livers.
When the livers and onions cool to room temperature, chop them coarsely. Scatter 2 crumbled hardcooked eggs over the mixture, and toss the livers gently to distribute the crumbles. Add 2 tablespoons chicken fat, and toss again. Taste the dish, and adjust the seasonings with salt and pepper.