Vinsetta Garage's whole grain gravy recipe

Today is National Cheese Curd Day and we are celebrating with a place that makes delicious beer-battered cheese curds.

Vinsetta Garage joined us on The Nine to tell us more about their cheese curds and other foods. You can hear from Chef de Cuisine Zack Kuhagen and get his whole grain gravy recipe below. 

Vinsetta Garage
Yield        1 qt
Prep tine    20 min
Cook time    20 min
Finish         40 min

1    Ea        onions chopped 
1    Ea        celery stalk chopped
1    Ea        Small carrots chopped
1    Tbl        tomato paste
1    Tbl        75/25 oil
½     Tsp        kosher salt for mirepoix
1/3     Tsp        pepper for mirepoix
1/4    Lb        butter
3.5    Oz        flour
1    Ea        garlic clove 
1     Ea        small bundle of Thyme sprigs
2    Tsp        peppercorn 
1    Ea        bay leaf
5    Cup        chicken stock
1.5    Tsp        kosher salt to finish
½     Tsp        pepper to finish
3    Tbl        whole grain mustard to finish

*With any recipe, it's important to read all instructions before starting to cook. This will help you to understand your next step and not miss any steps also. 

Season chopped carrots, onions, and celery with tomato paste, coat with oil and season with salt and pepper. Roast in oven on 375 until browned (approx. 5-10 mins.) This is referred to as Mirepoix.
Weigh thyme sprigs and secure with butcher's twine. Place garlic, bay leaves, and peppercorn into a cheesecloth or coffee filter and secure with butcher's twine. This is known as a Sachet (Sa-Shay.)
To avoid dropping the temperature of your sauce too rapidly, heat Chicken stock to a simmer. 
In a medium saucepot melt butter over medium heat until it foams, and add flour to make a Roux.
Cook roux for 5 min stirring frequently.
Add hot stock to Saucepot stirring frequently to prevent burning.
Add roasted mirepoix, and Sachet. Simmer for 20 min or until gravy has thickened.
Remove Sachet, and strain out mirepoix using a fine chinois. A colander will work as well, but A Chinois or fine strainer will yield more and provide a smoother finished gravy.  
Add remaining ingredients and mix well.