Tenderize the beef a bit. Heat oven to 80 C or 180 F. Place a plate below the rack in the middle. If you get meat with some fat crust leave it.

Slightly salt and pepper the slices.

Peel onions, cut them in thin rings. Dust them with a bit of flour.

In a large pan heat oil or clarified butter.

Brown the onion rings until they show a light brown color (15 min) on low to medium heat. If heat is too high they will get black. So the secret here is low heat and slow cooking.

When onions are done remove from pan, pat them with some kitchen paper to remove excess fat if needed, then wrap in aluminum foil and place into oven.

In the same pan on higher heat fry the meat slices, first 2 of them for about 1-2 min per side.

When done keep warm (wrap in foil). Repeat the same with other slices.

Place them on the oven rack with a plate below and roast for 15-30 min or until tender.

Alternatively you can also keep them in the pan on lower heat. Cooking time depends on the quality and thickness of the meat. Make sure they are not too long in the oven or pan because the meat will become dry. The meat should still show some slight red color inside, and should be tender and juicy.

Place the beef slices into the skillet.

Reduce heat of the pan, add the flour and red wine, whisk to get the fond from the bottom of the pan. Bring to a brief boil. add beef fond, let cook until the liquid has reduced 50 percent. Spice with salt and pepper to taste.

When beef is done place the slices on warm plates, place onion rings on top, add the side dish and finally the gravy.