PREPARATION

• Place a heavy-bottomed, large pot (one that easily holds a gallon) over medium-low heat. Add the butter and melt.
• Create a roux by adding the flour and stir well to combine. Add the Cajun spice, ground coriander, ground cumin, garlic powder, onion powder, ground Ancho chile and kosher salt. Allow to cook slowly for 5 to 7 minutes, stirring often to prevent scorching. Set aside.
• In another stock pot, combine the milk, cream and Dijon mustard; bring to a boil. Remove from the heat but keep warm. (At this point, you can also add both mixtures to your slow cooker and cook on low for 2 to 3 hours, stirring every 30 minutes.)
• Carefully and slowly, whisk the hot liquid into the hot roux until well combined.
• Simmer the sauce, stirring often and thoroughly to prevent scorching, until thickened properly.
• Remove the pot from the heat and add the green chiles, cheeses and jalapeno juice.
• Stir by hand or blend with an immersion blender until the cheese is melted and the sauce is smooth, or allow to cool to warm and then blend in batches in a stand blender.