If you're using ground beef in your Rotel dip, start by heating a large skillet over medium heat.
Add the ground beef and cook until browned, about 5-7 minutes. Break it apart with a wooden spoon as it cooks.
Once browned, drain any excess fat and season with salt, pepper, and garlic powder if desired. Set the beef aside.
While the beef is cooking, cut the Velveeta cheese into cubes to help it melt more evenly and quickly.
In a medium saucepan over medium heat (or in a microwave-safe bowl), add the cubed Velveeta cheese and the can of Rotel tomatoes (including the liquid).
Stir occasionally to help the cheese melt and blend with the tomatoes. This process should take about 5-7 minutes. Be careful not to let the cheese burn.
Once the cheese has melted, stir in the cooked ground beef and chopped onions (if using).
Continue stirring until everything is fully combined and heated through.
Once the Rotel dip is fully melted and smooth, remove it from heat.
Serve hot with tortilla chips, crackers, or veggies for dipping. You can also transfer the dip to a slow cooker set on low to keep it warm for parties.