Ingredients

10 ounces dried lentils
4 quarts beef stock, divided (see Beef Stock recipe)
1 cup salad oil
1 medium onion, chopped
1 cup chopped carrots
1 cup chopped celery
1 tablespoon garlic powder
1 tablespoons Greek oregano
1 1/2 teaspoons paprika
1 bay leaf
1 beef bouillon cube
2 teaspoons salt
1/2 teaspoon white pepper
1 cup flour
1 cup tomato sauce
5 tablespoons cider vinegar
Tomato paste as needed

Wash the lentils. Cover them with water and soak overnight.
Drain the lentils and bring them to a boil in 2 quarts of beef stock. Cook, uncovered, until tender, about 45 minutes. Expect to lose about half the liquid. Meanwhile, in another pot, combine salad oil, onion, carrots, celery, garlic powder, oregano, paprika, bay leaf, bouillon cube, salt and pepper. Saute the vegetables until tender, 6 to 8 minutes. Add flour and tomato sauce. Mix well and simmer at least 15 minutes, stirring occasionally. Add 2 quarts of beef stock and vinegar. Bring to a boil.
When the lentils are tender, add lentils and their cooking liquid to vegetables. Bring to a boil and simmer for at least 30 minutes. Add salt and pepper to taste. If desired, add 1 to 2 tablespoons of tomato paste for flavor and color.

Beef Stock

3 pounds beef bones
4 quarts cold water
1 stalk celery with leaves, coarsely chopped
1 large carrot, coarsely chopped
1 large onion, quartered
1 large tomato, quartered
6 black peppercorns
2 teaspoons salt
1 bay leaf

Directions

Wash beef bones, place in cold water. Bring to boil, skim surface scum as necessary.

Add celery, carrot, onion, tomato, peppercorns, salt and bay leaf. Simmer 3 to 4 hours. Strain, cool quickly and refrigerate. Remove hardened fat. If stock tastes too weak, boil to reduce further in order to concentrate flavor. Use as needed. Freeze if desired.