The Best Lentil Soup

2 T olive oil
1 md. onion (about a 1 1/2 C)
2 carrots, peeled, and chopped
2 celery stalk, chopped
8 C broth, veggie, or chicken
2 1/2 C lentils
1/4 C brown rice (optional it just adds more to the soup)
1 C peeled and chopped tomato (canned diced tomato will work too, I prefer Muir Glen brand)
1/2 lb fresh spinach
1/2 t coriander
1/2 t cumin
salt to taste ( I used a teaspoon, but it depends how salty your broth is)
balsamic for garnish (optional)

Saute the onion, carrots, and celery until they are soft. Add broth, lentils, brown rice, and tomato. Cook until soft, about 45 minutes on stove top, in a pressure cooker 10 minutes (they are worth their weight in gold). When the lentils and rice are soft, add in the spinach, coriander, cumin, and salt. Cook stirring the soup occasionally until the spinach is wilted. Serve hot, with a garnish of balsamic. This soup is really good the first day and equally good heated up the next.