01 - In a medium saucepan over medium heat, combine milk and heavy cream. Bring just to a simmer without boiling.
02 - Whisk in cream cheese until completely melted and smooth.
03 - Gradually stir in shredded white American cheese, a handful at a time, whisking constantly until fully melted and dip is smooth.
04 - Stir in diced jalapeño, green chilies, onion, and garlic. Cook for 2-3 minutes, stirring frequently, until vegetables soften.
05 - Add ground cumin, chili powder, salt, and white pepper. Adjust seasoning to taste.
06 - Reduce heat to low and keep warm until serving, stirring occasionally. If dip thickens, whisk in a splash of milk. Serve warm with tortilla chips.