01 - Combine whole milk and heavy cream in a medium saucepan over medium heat. Bring just to a simmer without boiling.
02 - Add cream cheese to the hot milk mixture, whisking constantly until fully melted and smooth.
03 - Gradually stir in shredded white American cheese, one handful at a time, whisking continuously until completely melted and the dip is smooth and creamy.
04 - Add diced jalapeño, green chilies, onion, and garlic. Cook for 2-3 minutes, stirring frequently, until vegetables soften.
05 - Stir in ground cumin, chili powder, salt, and white pepper. Taste and adjust seasonings as desired.
06 - Reduce heat to low and keep warm until serving, stirring occasionally. If the dip thickens too much, whisk in a splash of milk to reach desired consistency.
07 - Serve immediately with tortilla chips, fresh vegetables, or use as a nacho topping.