Short answers, pulled from the story.
A lentil is the lens-shaped edible seed of Vicia lens, also called Lens culinaris, an annual legume grown for its seeds, or pulses. The plant stands about 40 cm tall, and its seeds grow in pods that usually hold two seeds each.
The lentil was domesticated in the Fertile Crescent of the Near East and then spread to Europe, North Africa, and the Indo-Gangetic plain. The oldest known carbonized lentil remains come from Greece's Franchthi Cave and are dated to 11,000 BC.
In 2023, world production of dry lentils was 7 million tonnes, led by Australia, Canada, and India. Together those three countries accounted for 72% of the total.
Beluga Black lentils are named for their resemblance to beluga caviar. The cultivar behind them is Indianhead, named for the Indian Head research station in Canada, and it became a designer food in the 1990s after starting as a fodder crop.
Lentils require a cooking time of 10 to 40 minutes depending on the variety. Small husked varieties such as the common red lentil cook fastest and, unlike most legumes, do not require soaking.
Boiled lentils are 70% water, 20% carbohydrates, 9% protein, and 0.4% fat, providing 114 calories per 100 g. They are a rich source of folate at 45% of the Daily Value, along with copper and manganese.
The English word lentil derives from the Latin lens. Optical lenses, both those of the animal eye and artificial ones, got their name because their archetypal shape resembles that of a lentil.