Begin by heating a tablespoon of olive oil in a skillet over medium-high heat. Once shimmering, add the beef chunks and sear until browned on all sides, about 4-5 minutes. This step locks in flavor and creates a richer broth.
Transfer the seared beef to your slow cooker. In the same skillet, add a little more oil if needed and sauté the diced onion and minced garlic for 2-3 minutes until fragrant and translucent. Scrape up any browned bits from the pan, then transfer this mixture to the slow cooker.
Add the chopped carrots, parsnips, and potatoes to the slow cooker, distributing evenly over the beef and aromatics.
Pour the beef broth over all the ingredients, ensuring everything is partially submerged. Sprinkle the thyme, and season generously with salt and pepper to enhance flavor.
Place the lid on the slow cooker and set it to low. Allow the stew to cook undisturbed for about 8 hours, during which the vegetables will soften and melt into the broth, creating a thick, hearty consistency, and the beef will become meltingly tender.
Once cooking is complete, gently stir the stew to ensure the flavors are combined. The root vegetables should be very soft and integrated into a rich, slightly thickened broth. Check seasoning and adjust salt and pepper if needed.
Serve hot, spooning the hearty, aromatic stew into bowls. The dish offers a cozy, inviting appearance with chunks of beef and tender vegetables immersed in a thick, flavorful broth.
