Its a Mexican dish adopted by Americans and is made with lot of variations.
It's a dip served with tortilla chips.
For CHILE CON QUESO you will need:
3 tbsp oil
3 tbsp butter
1 cup thinly sliced onion
1 cup thinly sliced tomatoes
1/2 cup milk
1 cup grated cheese
2-3 tbsp water
5-6 green chillies (de seeded and cut into strips)
Salt and Pepper to taste
In a pan, take some butter and oil and then add the onions, saute till they are translucent, now add the tomatoes.
Once cooked add the chillies.
Now slowly add milk to the mixture and water if required. Add salt and pepper and cook stirring it constantly.
Remember you are making a dip for tortillas so the mixture shouldn't be runny, it should be thick and cheesy.
Finally add the cheese and cook until the cheese melts.
Serve with tortilla chips or try having it with any salty biscuits / crackers !