In a large saucepan, melt the butter over medium heat.
Whisk in the flour and cook for about 1 minute until smooth.
Slowly pour in the milk while whisking constantly so lumps don’t form.
Add the evaporated milk and continue stirring.
Cook for about 4 to 5 minutes until the sauce thickens slightly.
Lower the heat.
Add the cream cheese and stir until melted.
Gradually add the cheddar, Monterey Jack, and smoked gouda.
Stir slowly until the cheese melts completely into a smooth sauce.
Add garlic powder, onion powder, smoked paprika, black pepper, and salt.
The sauce should look silky and creamy.
If it seems too thick, add a splash of milk.
I noticed rushing the cheese step can make the sauce separate slightly, so now I add the cheese slowly.