Condensed Cream of Chicken Soup

4 tablespoons butter
4 tablespoons chicken fat (or use 4 additional tablespoons of butter)
1 ¼ cup onions, diced
1 cup carrots, diced
1 cup celery, diced
1 teaspoon kosher salt
¼ teaspoon freshly ground black pepper
¼ teaspoon freshly ground nutmeg
½ teaspoon dry mustard
1 teaspoon dry thyme
1 tablespoon dry parsley
2 tablespoons vermouth or white wine
½ cup all-purpose flour
4 cups chicken stock, heated 
2 ½ cups shredded cooked chicken

In a large Dutch oven or heavy bottomed pot over medium high heat, melt butter and chicken fat (or all butter if not using chicken fat) and add onions, carrots, celery, salt, pepper, nutmeg, mustard, thyme and parsley and cook for 10 minutes, stirring often.
    
Add vermouth or wine and cook just to evaporate wine.
    
Reduce heat to medium and add flour and stir with a wooden spoon to combine. Cook for three minutes stirring often.
    
Add stock in three pours using a whip to mix during each pour.
    
At this point, the mixture will be too thick to cook directly over a burner so defuse the heat with a heat diffuser and cook on medium to medium low for about ten minutes or until vegetables are tender. Remove from heat.
    
Using an immersion blender, puree until completely smooth and then add shredded cooked chicken.
    
To serve as cream of chicken soup, add enough whole milk or light cream or both to reach desired consistency.
    
Or use as-is in recipes calling for condensed cream of chicken soup.
    
Or freeze in zip lock bags. The mixture freezes very well as long as you have squeezed all of the air out before zipping up the bag and have not yet added milk or cream. Just thaw as needed for recipes calling for condensed cream of chicken soup.