On the stovetop, heat a skillet over medium heat.
Once the skillet is heated, add the butter, mushrooms, onion, and garlic and sauté until fragrant. The veggies do not have to be cooked completely.
Meanwhile, make the meatballs. Combine the ground beef, dried thyme, dried sage, garlic powder, and salt in a mixing bowl to combine.
Roll the meat into meatballs using a little oil on your hands if needed. Meatballs should be about golf ball size.
Once the veggies are done, remove them from the skillet and set aside.
Next, add your meatballs to the skillet and brown on each side for 3-4 minutes.
Once the meat is browned, turn off the stove. In the crockpot, add the bone broth, wine, and tomato paste. Stir.
Add the veggies and meatballs into the pot along with the bacon, carrots, and bay leaf.
Put the lid on the pot and cook on low for 3-4 hours.
Once the stew is done cooking, open the lid and remove the bay leaf (discard).
If you desire a thicker sauce, remove the meatballs and carrots from the pot and turn the temperature up to high.
In a small bowl, add the arrowroot starch to the half cup of water and stir to combine. Slowly pour in the arrowroot and water mixture into the pot while stirring until the sauce thickens (add more starch if needed).
Serve the stew on top of buttery mashed potatoes and finish each plate with a ladle or two of sauce and fresh thyme. Bon appetit!