In a medium saucepan over low heat, combine the 1 cup half and half and 1 tablespoon Argo corn starch. Whisk them together until the corn starch is fully dissolved.
Slowly increase the heat to medium, continuing to whisk frequently. As the mixture heats, it will start to thicken, which usually takes about 3-5 minutes.
Once your mixture begins to thicken, reduce the heat to low and gradually add in the 8 oz medium cheddar cheese, shredded. Stir gently until the cheese is completely melted and the dip is smooth.
Once the cheese is melted and the dip is creamy, remove it from the heat. Transfer your 3-Ingredient Queso Cheese Dip to a serving bowl and enjoy warm with your favorite chips or veggies!