Split & thoroughly wash leeks. Cut into chunks. Dice potaotes & chop the tomatoes. Thinly slice onions. Melt 3 tb ghee in pot & add onions & leek. Simmer very gently for 5 minutes. Add tomatoes followed by potatoes. Simmer gently for 2 minutes. Add stock. Bring to a boil. Stir in sugar, salt & pepper to taste. Reduce heat & simmer. Cook until potatoes are soft. Cool & then blend, using extra water if necessary.
Re-heat before serving. Top with croutons. Thin with water if desired. Will keep well in the fridge.
Nava Atlas, "Vegetariana"