Castilian Lentils from Salamanca The Castilian lentil is the largest of all lentils, with a size between 7 and 9 millimeters, and is light green in color with some darker grains, which are called "avinatadas lentils". The color of the Castilian lentil darkens over time. Its grain is wide, rounded, flattened, and shaped like a lens. These dried legumes have very thin skin and stand out for their tenderness and mild flavor. The Castilian lentil cooks excellently in any type of water.