01 - In a medium saucepan over medium heat, melt the 2 tablespoons of unsalted butter. Add the finely diced small onion and sauté for 2 to 3 minutes until softened. Stir in the 2 minced garlic cloves and the 2 finely diced jalapeños; cook for 1 minute until fragrant.
02 - Sprinkle in the 2 tablespoons of all-purpose flour and stir constantly for 1 minute to form a light roux.
03 - Slowly whisk in the 1 cup of whole milk, ensuring no lumps form. Cook, stirring frequently, until the mixture begins to visibly thicken, which should take approximately 2 to 3 minutes.
04 - Reduce the heat to medium-low. Add the 2 tablespoons of softened cream cheese and whisk until it is fully incorporated and the mixture is smooth.
05 - Gradually add the 2 cups of shredded sharp cheddar cheese and 1 cup of shredded Monterey Jack cheese, stirring continuously until both cheeses are completely melted and the dip achieves a creamy consistency.
06 - Stir in the 1/2 teaspoon of ground cumin, 1/2 teaspoon of smoked paprika, 1/4 teaspoon of salt, and 1/4 teaspoon of freshly ground black pepper. Taste the dip and adjust seasoning as needed to your preference.
07 - Transfer the warm queso dip to a serving bowl. If desired, garnish with 1 sliced jalapeño and 2 tablespoons of chopped fresh cilantro. Serve immediately with tortilla chips or fresh vegetables.