Beat eggs, sour cream, salt and pepper well or mix in a blender. Cook meat, onions and potatoes in butter and oil until onion is tender and potatoes are lightly browned.
Pour eggs mixture over all, lifting potatoes to let eggs run under. Cook slowly in a covered fry pan until eggs are set, 8 to 10 minutes. Sprinkle with cheese and serve.Makes 3 to 4 Source: