Roasted Flank Steak with Onion and Thyme

Remove the steak from the refrigerator a half hour before cooking. Cut away any tough connective tissue on the surface of the steak.

Sprinkle one side of the steak with dry mustard. Sprinkle the steak with salt and freshly ground pepper. Rub a tablespoon of butter all over the side of the steak. Turn the steak over and repeat with the dry mustard, salt, pepper, and butter.

Preheat the oven to 400 degrees. In a glass baking dish add the roughly chopped onions and garlic. Once the oven is preheated, add the onions and garlic to the oven to begin cooking.

Heat a large cast iron frying pan on high heat. Sprinkle both side of the steak with salt (unless you have used salted butter, then you can skip the salt. ) Place steak in hot pan. Let sear for 2 to 3 minutes until well browned. Use tongs to lift up to see if nicely browned. If so, flip to the other side and turn off the flame under the pan. Using tongs, gently place the seared flank steak over the onions and garlic in the baking dish and continue to cook for 5 to 10 minutes.

To check for doneness insert a meat thermometer into the thickest part of the steak - 120°F for very rare, 125°F for rare, or 130°F for medium rare. Flank steak should be served rare or medium rare, otherwise it may be too dry. Remove the steak from the pan to a cutting board and let rest for 10 minutes, covered with aluminum foil.