Bean soup is on the menu in the Senate's restaurant every day. There are several stories about the origin of that mandate, but none has been corroborated.
According to one story, the Senate’s bean soup tradition began early in the 20th-century at the request of Senator Fred Dubois
of Idaho. Another story attributes the request to Senator Knute Nelson
of Minnesota, who expressed his fondness for the soup in 1903.
The recipe attributed to Dubois includes mashed potatoes and makes a 5-gallon batch. The recipe served in the Senate today does not include mashed potatoes, but does include a braised onion. Both Senate recipes are below.
The Famous Senate Restaurant Bean Soup Recipe
2 pounds dried navy beans
four quarts hot water
1 1/2 pounds smoked ham hocks
1 onion, chopped
2 tablespoons butter
salt and pepper to taste
Wash the navy beans and run hot water through them until they are slightly whitened. Place beans into pot with hot water. Add ham hocks and simmer approximately three hours in a covered pot, stirring occasionally. Remove ham hocks and set aside to cool. Dice meat and return to soup. Lightly brown the onion in butter. Add to soup. Before serving, bring to a boil and season with salt and pepper. Serves 8.
Bean Soup Recipe (for five gallons)
3 pounds dried navy beans
2 pounds of ham and a ham bone
1 quart mashed potatoes
5 onions, chopped
2 stalks of celery, chopped
four cloves garlic, chopped
half a bunch of parsley, chopped
Clean the beans, then cook them dry. Add ham, bone and water and bring to a boil. Add potatoes and mix thoroughly. Add chopped vegetables and bring to a boil. Simmer for one hour before serving.
The above is from the U.S. Senate website. Here is the recipe that I use.
U.S. Senate Bean Soup
1 lb. dried navy or great northern beans, sorted, soaked overnight, and drained
12 cups cold water
2 meaty smoked ham hocks (2 lbs.)
3 cups chopped onion
2 cups chopped celery
1 cup mashed potatoes
3 gloves garlic, minced
1/2 teaspoon black pepper
1 teaspoon thyme leaves
In an large pot, bring beans, water, and ham hocks to boil over high heat. Lower heat and simmer, covered, stirring occasionally and skimming the surface, for 1 hour or until the beans are tender.
Stir in onions, celery, mashed potatoes, and garlic. Season with pepper and thyme. Raise heat to high and bring to boil. Lower heat and simmer , covered for 1 hour or until vegetables are tender, stirring occasionally.
Using a slotted spoon, transfer ham hocks to a cutting board. When cool enough to handle, cut meat into bite sized pieces, discarding the bones, and stir back into the soup.