Fava Puree

Place beans in a bowl, cover with water and soak overnight. Drain and remove skins. Heat oil in a large saucepan , add onions and saute until softened, 5 to 7 minutes. Add the reserved beans, sugar , salt to taste, and water. Stir to blend, then cover pan and simmer for 45 minutes, or until beans are very soft. Add the lemon juice, simmer for 5 more minutes, and taste for seasoning. Puree bean mixture in a blender or food processor until smooth, then transfer to a bowl and chill until firm. To serve, either garnish the top with fresh dill, or invert puree onto a serving dish and garnish with the dill and lemon slices.