Bison soup

Bison soup bones	2 ½ pounds
Butter	2 tablespoons
Onions, medium, chopped	2
Carrots, medium, chopped	2
Celery, sliced	2 sticks
Bacon strip, chopped	1
Beef stock	8 cups
Bouquet garni using cheesecloth thyme  parsley marjoram  rosemary bay leaves	3 sprigs 3 sprigs 2 sprigs 3 sprigs 2
Flour	2 tablespoons
Lemon juice	½ lemon
Port or sherry, the good stuff	4 tablespoons
Salt
Pepper, freshly ground

1. In a large pan, melt the butter, and then add the bison bones in batches, if necessary, and brown them quickly on all sides; transfer to a plate. 
2. In the same pan, add the onions, carrots, celery, and bacon; cook for 5 to 10 minutes, stirring occasionally, until the vegetables are softened and golden. 
3. Return the bison to the pan, and add the stock and bouquet garni. 
4. Bring just to a boil, and skim off any foam. 
5. Cover and simmer gently for 3 hours, or until the meat is so tender it falls from the bones. 
6. Strain, and discard the vegetables and bouquet garni; leave to cool slightly. 
7. Remove the meat from the bones, and shred into small pieces; discard bones. 
8. Skim any fat that has risen on the stock, return to a large pan, add the meat, and reheat. 
9. Whisk together the flour with a little cold water to make a smooth paste. 
10. Stir in a little hot stock, and then add and stir into the pan. 
11. Bring the soup to a boil, stirring, until it thickens slightly. 
12. Reduce the heat, and simmer gently for about 5 to 10 minutes. 
13. Season with salt, pepper, and lemon juice to taste. 
14. Stir in the port or sherry, and serve in warmed soup bowls.