In a large saucepan put the lentils and about 9 cups of water, place on high heat. Bring
to a boil, reduce the heat to medium and add the Swiss Chard. Cover and boil gently for 15 minutes.
Meanwhile heat the olive oil in a skillet, add onions. Cook on medium heat until translucent; add the garlic paste and cilantro and cook gently for 3 minutes; transfer to the saucepan and mix well with the softened chard and the lentils.
Continue cooking covered for another 45 minutes until the lentils are tender.
Slowly incorporate the lemon juice, season with salt and pepper; simmer uncovered for 5 minutes.
Taste and adjust seasoning if necessary, serve at room temperature.
In the winter I tend to add potatoes to this soup, making it more hearty. This soup is nice and tart.