Castilian Lentils from Salamanca The Castilian lentil is the largest of all lentils, with a size between 7 and 9 millimeters, and they are green lentils with a light color and some darker grains, which are called "avinated lentils". The color of the Castilian lentil darkens over time. Its grain is wide, round, 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.