Season beef with 1 tsp. salt and pepper in a medium bowl. Toss with flour until evenly coated. Heat 3 Tbsp. oil in a 6-qt. Dutch oven or large, heavy-bottomed saucepan over medium heat. Shake off excess flour and brown beef in 3 batches, 4 to 6 minutes per batch. To avoid scorching add 1 extra tablespoon of oil and lower the heat slightly, as necessary.

Return all meat and the juices to the pan. Stir in yellow onion, tomato paste and garlic; cook about 1 minute, scraping up any brown bits from the bottom of the pan, until the tomato paste turns a darker brick-red color.

Add wine and cook 1 minute. Add the stock, mushrooms and thyme; bring to a boil over high heat.  Reduce heat to low, cover and simmer gently for 30 minutes.

Add pearl onions, potatoes, carrots and remaining 1/2 tsp. salt. Bring to a boil over high heat. Reduce heat to low, cover and simmer 20 minutes or until potatoes are cooked through. For a thicker soup, uncover and simmer 10 more minutes.  Season to taste with salt.

To serve, remove thyme sprigs and stir in 1/4 cup parsley.  To serve, ladle soup into individual bowls and sprinkle with remaining parsley.