Cube the white American cheese into small pieces.
Shred the Monterey Jack cheese if needed.
Chop the onion into tiny pieces.
Mince the garlic cloves finely.
Open the can of green chiles.
Having everything ready makes cooking easier.
Melt butter in a large pot over medium heat.
Add the chopped onion to the pot.
Cook for 3-4 minutes until soft.
Add the minced garlic and cook 1 minute more.
The kitchen will smell amazing already!
Pour in the whole milk and heavy cream.
Stir everything together well.
Let it warm up but don't boil.
Keep the heat on medium-low now.
Add the white American cheese cubes gradually.
Stir constantly as the cheese melts.
Add the Monterey Jack cheese next.
Keep stirring until everything is smooth and creamy.
This takes about 5-7 minutes.
Stir in the diced green chiles.
Add the cumin for extra flavor.
Taste and add salt if needed.
Mix everything together well.
Pour the queso into a serving bowl.
Garnish with fresh cilantro if you like.
Serve immediately with tortilla chips.
Keep it warm for best results.