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, round, flattened, and lentil-shaped. These dry legumes have very thin skin and stand out for their tenderness and mild flavor. The Castilian lentil cooks excellently in any type of water.