Grilled Marinated Beef Fillet With a Tangy Sauce

READY IN: 25mins
Recipe by The Flying Chef

Marinated steak served on a bed of mash, topped with spinach and drizzled with a tangy sauce. I served mine on parsnip mash, but you can serve steak with whatever vegetable or potato you like, mine is only a serving suggestion. You can also use beef sirloin, rib-eye or rump steak instead of beef fillet.

Top Review by TasteTester

I served this to guests who flew in tonight; they were so hungry (airline peanuts just don't do the trick). The sauce was so delicious on the mashed potatoes I used as a base, and on the spinach as well. I think I might use add more beef base next time and season the steaks with salt, but our guests loved it; there were no leftovers. None of us had used a mustard-vinegar marinade on steak before, but it gave a great flavor overall. Also, the presentation was great -- quite impressive my guests said. Thanks for posting this!!

Ingredients Nutrition


  1. Combine vinegar, oil and mustard's in storage container add steaks and marinate several hours or overnight.
  2. Drain beef and reserve marinade. In a medium saucepan add stock, sugar and water to reserved marinade. Heat over medium heat until sugar dissolves. Mix a little water with cornflour and add to sauce, stir until mixture thickens. Keep warm over low heat stirring occasionally. If sauce seems to be getting too thick add a little more water, not to much though, as remember you still have to add the sour cream which will thin it out again.
  3. Heat a small amount of olive oil in a pan over med high heat (or grill or BBQ) add the steaks and sear 1-2 minutes each side. Cook for a further 4-5 Min's a side for medium rare. Cooking time will vary depending on the thickness of the meat. Remove steaks and allow to rest.
  4. While the steak rests, turn up the heat on the sauce and whisk in sour cream (this will also blend in any mustard that is still a little lumpy.), add pepper to taste.
  5. To serve: Place a few spoonfuls of desired mash in the centre of a plate, place steak on top and top with a mound of spinach, drizzle with sauce.

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