In Swahili they are called 'ndengu', in Italian 'fagioli verdi indiani' or mungo beans, from the Indian 'Moong Daal'. The plant's Latin name is 'Vigna radiata' and it is a leguminous plant.
In Kenyan markets, these beans are also found in pods or already shelled, in large bags at the foot of stalls or outside small shops selling grains and cereals.
There are many local recipes for preparing stewed ndengu, but the tastiest is the one that involves oriental spices and a few little secrets that the Asian community that has been present in Kenya for more than a century has handed down from generation to generation.
Here is the recipe we learnt from them (ingredients for 4 persons):

Procure about 250 grams of ndengu and soak them in water for a few hours.
Heat just under a litre of water in a pot, add the ndengu and cover with a lid.
Once the water boils, let them simmer for about twenty minutes.

Prepare a chopped onion, ginger and garlic. Add a sprinkling of pepper, salt and a few drops of lemon. Create a sort of paste.

Cut 4 tomatoes into cubes.
Finish cooking the ndengu, drain and save some of the cooking water.
Heat oil in a large frying pan, add the onion, garlic and ginger paste and fry.
Add the tomatoes and cook for 5 minutes.
Add two ladlefuls of cooking water and stir in one tablespoon of paprika, one teaspoon of cumin powder and one teaspoon of turmeric. Cloves or a cinnamon stick can also be added at your discretion.
After another 5 minutes, add the ndengu and cook for a further 10 minutes.
If necessary, add more water.
At the time of presentation, you can garnish with coriander (in Kenya this is most commonly used) or parsley.
The 'moong daal' stew can become a main dish if served with pre-cooked basmati rice that has been left in the refrigerator (this removes starches and carbohydrates) and then heated in the oven with butter, oil, yoghurt or coconut milk to taste. It can also be served with chapati or Indian naan.