For hard gainers and heavy bulking phases: this is a calorie-maximum meal, not an everyday plate. Slow-simmered chuck in a mushroom and sour cream sauce over a big bowl of buttered egg noodles.
Pat the beef dry, toss with the flour, salt and pepper.
Melt half the butter in a heavy pot over medium-high heat and brown the beef in two batches, about 4 minutes per batch. Set aside.
Lower the heat to medium, cook the onion and mushrooms for 8 minutes until browned. Return the beef, add the broth and Dijon, cover and simmer over low heat for 1 1/2 hours, until the beef is tender and well past 71°C (160°F) inside.
Cook the egg noodles in boiling salted water over high heat for about 7 minutes, drain and toss with the rest of the butter.
Take the beef off the heat and stir in the sour cream; do not boil it or it will split.
Spoon the stroganoff over the noodles and scatter with parsley.