- 2 tbsp. chopped parsley
- 1 cup finely chopped onion
- 3 cups mushroom caps sliced
- 2 lbs. sirloin cut into strips
- 1-1/2 tbsp. powdered mustard
- 1/2 cup sour cream
- 3 tbsp. unsweetened ketchup
- 3 tbsp. oil
- freshly ground white pepper
- salt to taste
Combine mustard powder, ketchup, and enough hot water to form thick paste.
Sauté onions and mushrooms in 2 tbsp. of oil until golden and soft. Remove with slotted spoon to preheated Dutch oven.
Add remaining oil to skillet and sauté meat strips in batches (quickly, like in stir-frying). Transfer meat to Dutch oven.
Put mustard paste and sour cream in skillet with any remaining juices. Stir gently all ingredients until smoothly mixed.
Pour over meat and onions and mix well. Gently simmer until hot. Sprinkle with parsley, salt, and freshly ground white pepper and serve immediately.