Greek Lentil Soup

Heat 1/4 - 1/2 c. of water in a 5-qt. pot and saut onion about 3 min. until limp. Add celery, carrots, liquid, and bay leaf. Bring to a boil, cover, and simmer on low heat about 45 minutes until lentils are tender. Add salt, greens (I've made this with both Swiss chard and collard greens and much prefer it with the collards), and shells, cover, and cook 15 min. or until shells are tender. If soup appears to be too dry at this time, add more liquid. (This should be a thick, stewlike soup, but, if heat is too high, there may be too much evaporation.) When fully cooked, stir in lemon juice to taste. Chili paste or hot sauce may also be added to the pot at this time, or may be added to each person's bowl, to taste, at the table. I prefer to serve it the second way, so that I can make my own as hot as I like with no compunction!