In a medium saucepan over low heat, combine shredded cheese, milk, and heavy cream, stirring until the cheese melts.
Add green chilies, jalapeño (if using), garlic powder, and onion powder. Mix well.
Cook over low heat, stirring frequently, until smooth and creamy. Adjust consistency with a splash of milk if needed.
Season with salt to taste and remove from heat. Transfer to a serving bowl and garnish with fresh cilantro if desired.
Serve immediately with tortilla chips and enjoy warm.