Recipe: Ob Goosht (Lamb Shank Stew)

I cannot lose this recipe, so it's being recorded here:

2 lbs lamb shank
3 potatoes (with peel)
2 tbsp tarragon
2 cans garbanzo beans
1 can great northern beans
1 can tomato paste
2 tbsp lemon powder
salt & pepper
1/2 onion, chopped

Put lamb shanks, tarragon, lemon powder, and onion in large pot with water to cover; boil. Add salt, pepper, and potatoes. Cook until tender (2 hours or more), covered. Add beans and tomato paste and simmer with lid off for 30 minutes.
Remove potatoes and skin them. Smash one up and return it to the pot. Remove shanks from the pot and shred meat from them while simmering stew. Strain broth from stew and mash or blend beans, etc. until almost smooth. Dish this into bowls, add shredded meat on top, and pour broth around it. Eat with bread.