Put the lard or oil and butter into a pot. When it is hot, add the chicken pieces and cook until brown. Add the onion and saute over a low fire until onion is soft (about 5 minutes).
Into the pot go the tomatoes, buttermilk, sugar, salts, pepper and pepper sauce. Allow this mixture to simmer for about 25 minutes.
After the 25 minutes, add the green onions, parsley and dill. Cook, uncovered, about 5 minutes longer.
Finally, the lemon juice and sour cream are stirred in and heated.