In a large bowl combine your beef with the garlic, onion, and seasonings. Stir until evenly coated. Place it into the bottom of your slow cooker. Add the water and top with the butter. Slow cook on low for 4-6 hours or high for 4 hours, until the meat, is tender.
When ready to serve make the queso. In a medium saucepan add your Velveeta cheese and drained tomatoes and chiles. Stir over medium-low heat until everything is melted. Using a slotted spoon remove the steak bites from the slow cooker and serve with the queso for dipping.