Lentil Soup

This soup gives Tim nightmares. He says I fed it to them ALL THE TIME, when they were kids growing up. Well, I guess it would seem like that when it's something you don't like. But for those of us who like lentil soup it's a nutritios meal, and another good way to use that ham bone . . .  Just don't fix it if Tim's coming for dinner.

2 cups dried lentils
1 meaty ham bone
1 cup diced celery, with tops
1/2 cup diced onion
1 cup diced carrots
1 tsp sugar
1/2 tsp thyme
1 bay leaf
2 Tbs butter
2 Tbs flour
1/2 lemon, juiced
2 tsp salt
1/4 tsp pepper
Fresh chopped green onions

Cover lentils with water. Swish around to wash them; drain. Cover with water again and let soak overnight. Drain and save liquid.

Put lentils in a large kettle. Add enough water to saved liquid to equal 9 cups. Add lentils and ham bone. Cover and simmer for 3 hours.

Add celery, onion, carrots, sugar, thyme, and bay leaf. Cover and return to a simmer. Continue to simmer for 30 minutes.

Remove ham bone. As soon as it is cool enough to handle, remove the meat. Chop up and return to soup pot.

Melt butter in a saucepan. Add flour, and a small amount of the soup. Mix well. Stir this back into the soup pot. Stir constantly until it comes to a boil. Add lemon juice, salt, and pepper.

When serving, sprinkle each serving bowl with chopped green onions.