In a large Dutch oven, cook the ground beef and diced onion over medium-high heat for about 7 minutes until beef is cooked through and onions are lightly caramelized. Break up the beef as it cooks and stir often. Drain excess fat if necessary.

Add the taco seasoning and water to the beef mixture. Stir to combine well.

Stir in the diced tomatoes and green chiles (Ro-Tel). Lower heat to medium-low.

Add the diced Velveeta cheese. Cover and cook, stirring every minute or so, until the cheese melts completely and the dip is smooth.

Garnish with chopped cilantro leaves before serving. Serve warm with tortilla chips.