Step 1: Season the roast - Pat the chuck roast dry with paper towels, then season all sides evenly with salt, black pepper, smoked paprika, onion powder, and garlic powder. This simple seasoning builds the foundation of flavor.
Step 2: Sear for flavor - Heat a large skillet over medium high heat and melt the butter. Once hot, sear the roast on all sides until nicely browned. This step adds deep flavor you cannot get from slow cooking alone.
Step 3: Transfer to slow cooker - Place the seared roast into the slow cooker, settling it into the center.
Step 4: Add the vegetables - Arrange the halved baby potatoes, carrots, and sliced onion around the roast. Try to keep the vegetables evenly sized so they cook at the same rate.
Step 5: Mix the sauce - In a bowl, whisk together the Coca Cola, Worcestershire sauce, beefy onion soup mix, brown gravy mix, and minced garlic until smooth and well combined.
Step 6: Pour and cook - Pour the sauce evenly over the roast and vegetables. Cover and cook on low for 8 hours or high for 6 hours until the beef is fork tender and easily falls apart.
Step 7: Garnish and serve - Sprinkle with fresh parsley if desired and serve hot with plenty of gravy spooned over the top.