2 Tbsp. butter
1/2 yellow onion, diced
2 serrano chilies, seeded and minced
1 jalapeño, seeded and minced
2 cloves garlic, minced
2 Tbsp. flour
1 cup milk
1 Tbsp. cilantro
4 roma tomatoes, diced
12 oz. cheddar cheese, grated
12 oz. monterey jack cheese, grated
1/2 cup sour cream

  • Sauté vegetables in butter until tender.
  • Mix in flour and cook for 30 seconds.
  • Add milk slowly and whisk constantly until thickened.
  • Reduce heat and add cilantro and tomatoes.
  • Add cheese in small batches, whisking until combined.
  • Add sour cream and mix thoroughly.

Source: http://www.browneyedbaker.com/chile-con-queso-dip-recipe/