<human>:  How do I make a roux for a cheese sauce?
<bot>: To make a roux for a cheese sauce, start with equal parts of melted butter and all-purpose flour in a saucepan. Stir together over medium-low heat until the mixture has thickened and is slightly golden. Continue to cook, stirring constantly, for about 3 minutes. Add in 1 ½ cups of milk and bring the mixture to a boil. Reduce the heat to low and simmer, stirring constantly, for 3 minutes or until the sauce has thickened. Add in the desired amount of cheese and stir until fully combined. Serve the cheese sauce with your favorite dishes.