Oats. Along with peanut butter, oatmeal for breakfast was introduced by Greek Americans, and often called just 'Quaker' (pronounced 'quacker' by those who never lived in America).
πόριτζ βρώμης (póritz brómis): porridge oats
νιφάδες βρόμης (nifádes brómis): rolled oats.
Image by Hankwang