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Combine the beef seasoning and set aside. Measure and set out all additional ingredients.
Cut meat into 1-inch cubes, discard any large pieces of fat. Fat marbleized into the meat is fine!
Sprinkle the meat with the seasoning mixture and toss to coat. Sprinkle with flour and toss to coat again.
Heat 3 Tablespoons olive oil in a large skillet over medium high heat. Add the meat in batches, don’t overcrowd the pan). Brown on each side for 30-40 seconds and set aside on a plate. Add more oil in between batches as needed. (The middle of the meat should still be red and cold!)
Turn the heat off. Carefully wipe up any very black spots but leave the brown remnants on the bottom of the pan. This is called ‘fond’ and will give the soup plenty of flavor.
Once the pan has cooled a bit, add the wine and turn heat up to medium-high. Use a silicone spatula to “clean” (deglaze) the bottom of the pan. Watch it carefully while it reduces.
After 3-5 minutes, or once the liquid has reduced by half, add 2 TBS butter and the diced onions. Cook for 4 minutes.
Add the garlic and cook for 1 more minute. By now the wine should be almost completely gone with only red colored onions left.
Add everything else except cornstarch mixture and vegetables: (Browned beef, Tomato paste, Worcestershire sauce, bay leaves, rosemary, ground sage, beef broth, and 1 beef bouillon cube.)
Cover the pot, leaving just a small crack, and simmer over medium-low heat for 2 hours (or more). The liquid should simmer softly and reduce slowly with a little bit of steam escaping.
Once ready to serve, prepare cornstarch mixture. Add ¼ cup of cornstarch to a small Tupperware container. Add ¼ cup COLD water. Cover and shake to combine.
Bring the soup to a full boil. Slowly add the cornstarch mixture in increments, using a silicone spatula to carefully stir it in as you do so. If the soup reaches your desired level of thickness before the cornstarch mixture is gone, you can refrain from adding the rest. (I like to add it all!)
Reduce heat to low. Add in the frozen vegetables and stir to combine. Heat for 10 minutes. (If a darker color is preferred, add up to 3 drops of Gravy Master.)
Remove from heat. Remove the bay leaves and rosemary stem. Swirl in 2 Tablespoons of cold butter for a smooth, velvety finish. This is a technique that chefs use called “monter au beurre”.
Garnish with chopped parsley and serve over mashed potatoes or with biscuits.