In a skillet over high heat, saute half of the chicken livers in 1 tablespoons olive oil until browned but still pink inside. Season with salt and pepper. Set aside on a plate and loosely tent with foil. Repeat with the remaining livers and another 1 tablespoons olive oil.
In the same skillet over medium heat, soften the shallots in the remaining olive 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.