In a medium saucepan, combine the chicken stock, green lentils and bay leaf. Bring to a boil, then cover and simmer over low heat, stirring occasionally, until the lentils are tender, about 45 minutes. Uncover and boil the lentils over high heat until most of the liquid has evaporated, about 2 minutes. Discard the bay leaf and let the lentils cool slightly.

Transfer the cooked lentils to a food processor. Add the chopped garlic, tahini, olive oil and lemon juice and puree until smooth. Scrape the hummus into a bowl, stir in the cumin and 2 tablespoons of the chopped cilantro and season with salt and cayenne. Garnish the hummus with paprika and the remaining 2 tablespoons of chopped cilantro. Serve the lentil hummus warm or at room temperature with pita chips and vegetable crudites.

The lentil hummus can be refrigerated overnight. Let return to room temperature before serving.