In a skillet over high heat, sauté half the livers in 15 ml (1 tablespoon) oil until browned but still pink inside. Sea-son with salt and pepper. Set aside on a plate and loosely tent with aluminum foil. Repeat with the remaining livers and another 15 ml (1 tablespoon) oil.
In the same skillet over medium heat, soften the shallots in the remaining oil. Deglaze with the vinegar. Reduce until all liquid has evaporated. Add the maple syrup and port and reduce until syrupy. Season with salt and pepper. Add the livers and reheat, coating thoroughly with sauce. Adjust the seasoning.