Chop then cook onions in butter until half done in a medium skillet. Add in mushrooms and sherry. Cook until mushrooms are almost done.
In a large pot add broth, cooked mushrooms, and cooked onions. Cook over medium heat.
Sear stew beef in the same pot you cooked the mushrooms in. Add to the pot, and reduce heat to low. Also add in sausage. Simmer for 15-20 minutes to help infuse flavors. In last 5 minutes add milk and flour.
Turn off the heat. Add dill, paprika, lemon juice, and sherry.