01 - In a medium saucepan over medium heat, melt the butter. Add the finely diced onion and sauté for 2 to 3 minutes until softened. Stir in the minced garlic and diced jalapeños; cook for 1 additional minute until fragrant.
02 - Sprinkle in the all-purpose flour and stir constantly for 1 minute to create a roux.
03 - Gradually whisk in the whole milk, ensuring a smooth consistency without lumps. Continue cooking, stirring frequently, until the mixture begins to visibly thicken, approximately 2 to 3 minutes.
04 - Reduce the heat to medium-low. Add the softened cream cheese and whisk until it is fully incorporated and the mixture is smooth.
05 - Incrementally add the shredded sharp cheddar and Monterey Jack cheeses, stirring continuously until all the cheese is fully melted and the dip achieves a creamy, uniform texture.
06 - Stir in the ground cumin, smoked paprika, salt, and freshly ground black pepper. Taste the dip and adjust the seasoning as necessary to your preference.
07 - Transfer the prepared queso to a serving bowl. Garnish with jalapeño rings and chopped fresh cilantro, if desired. Serve warm alongside tortilla chips or an assortment of fresh vegetables.