red lentil and lime soup

this soup sounds really exotic, but it has mass appeal. plus, it's an adventure to make from beginning to end; from colour-changing lentils to sour soup.

ingredients:
2 cups split red lentils, picked over and rinsed several times
salt
4 T butter
1 large onion, diced
1 t ground mustard
2 t ground cumin
2.5 quarts water
juice from three limes
handful fresh cilantro
optional:
1 cup cooked rice
1/2 cup yogurt
1 large bunch fresh spinach, chopped

instructions:
-bring to boil lentils in 2 1/2 quarts water, 1 T salt, and 1 T butter. cover and simmer for 20 minutes. lentils will turn yellow and break apart.
-while lentils are cooking, saute onions in medium saucepan in 2 T butter, cumin and mustard.
-when onions are soft, add cilantro and saute 1 more minute.
-when lentils are done, add onion mixture to the lentils.
-add 2/3 of lime juice. taste and add more if necessary. soup should be sour and i usually add all the juice.
-cover and cook for 35 minutes.

optional:
-put a spoonful of rice in the bottom of each bowl before ladeling in soup.
-right before serving, fry spinach in 1 T butter with a pinch of salt until spinach in bright green. put a generous amount in the bottom of each bowl before ladeling in soup.
-serve yogurt on the table in a small bowl, and have audience stir a spoonful into their soup.
-you may do all three of these things together.

serves 6-8

original recipe comes from vegetarian cooking for everyone, by deborah madison, broadway books, 1997. changes made by devon.