In a large skillet or Dutch oven, heat the olive oil and add as many meat cubes as you can without crowding (if the skillet is too crowded, the meat won't brown properly.) Brown the meat well on all sides, remove each batch as it browns and set them aside. It may be necessary to add a little more olive oil.
When all of the beef has been browned and removed, add the onions to the remaining juices in the skillet and cook, stirring occasionally, until they are golden brown. Add the mushrooms and cook until they have released most of their water. Sprinkle the mushrooms with the flour, add the garlic, the remainder of the ingredients except for the sour cream and the chives. Add the beef cubes back to the pot. Bring to boil, reduce to low heat, cover and cook for about 2½ to 3 hours or until the beef is very tender.
In a small glass bowl, add the sour cream. Add a couple spoon of the hot sauce to temper. Remove the pot from the heat and just before serving, add the tempered sour cream and sprinkle with chopped chives.