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