Begin by placing your cubed beef in a large plastic bag. Combine a quarter cup of flour with the salt in a small bowl. Pour the flour mixture into the bag with the beef. Seal the bag and shake it well to coat all the pieces evenly. This step not only helps to season the meat but also thickens the stew later on.

In a large skillet, heat the olive oil over medium-high heat. Add the floured beef in batches (don’t crowd the skillet) and cook until each piece is golden brown on all sides. This browning process enriches the stew’s flavor. Once browned, transfer the meat to your slow cooker.

In the same skillet, melt the butter. Add the sliced onions and sauté them until softened, which should take about 5-7 minutes. This will caramelize the onions slightly, adding sweetness to your stew. Once done, toss them into the slow cooker with the beef.

Pour the red wine into the skillet, scraping the bottom with a wooden spoon to loosen all those flavorful browned bits stuck to the pan. Once it’s well mixed, remove it from heat, and pour this mixture into the slow cooker.

Now, add the diced potatoes, baby carrots, dried thyme, and black pepper to the slow cooker. Stir everything together to ensure it gets mixed up nicely.

In a separate bowl, stir the boiling water together with the onion soup mix until dissolved, then pour it into the slow cooker. Cover the slow cooker and cook on high for about 30 minutes. Then, reduce the heat to low and let it simmer away for 6 hours. Your kitchen will smell fantastic!

Once the cooking time is up, create a slurry by mixing ¼ cup of warm water with 2 tablespoons of flour in a small bowl. Stir this mixture into your stew, keeping the slow cooker uncovered. Allow it to cook for another 15 minutes, just until it thickens to your desired consistency.