With Thanksgiving around the corner, the sales of canned cream of mushroom soup are off the charts. In fact, 40% of the entire year's sales of Campbell’s cream of mushroom soup are attributed to the beloved green bean casserole. This iconic dish is about to adorn 20 million Midwestern tables during the upcoming Thanksgiving holiday. When I was growing up, every Thanksgiving meal included green bean casserole, and in fact we loved it so much, we served it again at Christmas.
Dorcas Reilly invented the green bean casserole for Campbells in 1955. It really was a genius idea, it turned Campbell’s lowly cream of mushroom soup into a sauce! I have been teaching people how to make sauces and soups for over 25 years now. In every soup or sauce class I teach, I share this nugget, “Soup is Sauce”, sauce is just thicker than soup. As many times as I have said “Soup is Sauce” I don’t think students really believe me, but cream of mushroom soup proves it!
Cream of mushroom soup is a velouté (not a cream sauce); it is a thickened white stock that is finished with cream. I can be eaten like a soup or I can pour it in my green bean casserole or finish a piece of poached salmon or egg with it. Julia Child didn’t release her epic tome, Mastering the Art of French Cooking until 1961, six years after Dorcas Reilly invented the green bean casserole. It could be said that the presence of French sauces and soups in American cooking could more fairly be attributed to Dorcas Reilly and the green bean casserole rather than to the icon of American French cooking, Julia Child.
Grandma and Grandpa’s Thanksgiving Table
When I was growing up, our Thanksgiving meal was served at noon sharp. My family’s feeling was that Thanksgiving was so good the first time you should be able to eat it twice! We ate our first Thanksgiving meal at noon. We ate pie after the first meal, and my grandmother Ruby would generally make six to eight different types of pies so it took all afternoon to navigate which kind of pie to eat. We then ate another Thanksgiving meal in the late afternoon or early evening. As a guest this was pretty awesome, as a host this is a whole lot of work and a heck of a lot of dishes!
When I host Thanksgiving, I love to serve a soup midday rather than an early Thanksgiving. It is a lot easier than putting out a bunch of cheese, crackers and appetizers. It also tends to satisfy peoples' appetites without filling them up. Serve this recipe as a soup or elevate your green bean casserole during the upcoming holiday season, either way you’ll be sure to wow your guests.
Cream of Mushroom Soup
Scroll down for a printable version of this recipe
Yield: 10 cups
Prep Time: 10 minutes
Cook Time: 1 hour
1/4 cup butter
1 large yellow onion, small dice
2 1/2 pounds button or cremini mushrooms, cleaned and sliced
1/4 cup all-purpose flour (increase to 1/2 cup for green bean casserole consistency)
2 quarts water
3 Tablespoons sherry vinegar or apple cider vinegar
2 bay leaves
1 teaspoon dried thyme or tarragon
1/4 cup to 1 cup of heavy cream
1/4 cup celery leaves, medium chop
Salt and pepper to taste
Step 1: Sauté Onions and Mushrooms
Wipe clean or rinse and dry the mushrooms prior to slicing the mushrooms.
Preheat a 5 1/2 quart French oven or heavy gauge stock pot over a medium heat. Add butter and onions and sauté for approximately 5 minutes, until the onions are soft and translucent.
Add the mushrooms to the onions and sauté approximately 20 minutes, stirring occasionally. The mushrooms will only start to brown once most of the liquid from the mushrooms have evaporated. You will see the steam rising from the pan start to diminish and at that point the mushrooms will start to caramelize and brown. This browning adds a lot flavor to your soup and will be the base for the stock for the soup.
Step 2: Make the Roux
After the mushrooms have browned, lightly add the flour to the mushrooms and sauté for a minute or two. This helps to remove the raw starchy taste of the flour. Do not over sauté since the longer the flour is cooked the less ability it has to thicken.
The flour combined with the butter that the mushrooms were sautéed in creates a roux. The roux is what will thicken your soup, the more roux per ratio of liquid the thicker the soup. This recipe is for a soup consistency, if you want to use it in your green bean casserole, you can add an additional 1/4 cup of flour for sauce consistency.
Step 3: Simmer and Season
Add the room temperature or cold water to the mushroom/roux mixture. The cooler liquid helps to stop lumps from forming. Once you add the water mix well until all the flour is dissolved. Add the vinegar, bay leaves and thyme, simmer for approximately 30 minutes stirring and scraping down the sides of the pans frequently.
Remove bay leaves and season with salt and pepper to taste. Add the celery leaves. You do not need to add cream to this recipe but if you choose to, start with 1/4 cup and add up to a cup. It is really up to you on how rich and creamy you want the soup to be. Simmer 2 or 3 minutes until cream is warm and celery leaves are wilted.
I hope you have a wonderful holiday season and enjoy this recipe, whether in your green bean casserole or served as an elegant accompaniment to your holiday meal.
If you want to learn the foundations of sauce making, mark your calendars now for Sauce Boot Camp coming up on Saturday, February 18, 2023 at 10am at Lincoln Square. If are looking for more tips and tricks for holiday entertaining, we have some fun cooking and baking classes coming up this season:
- Hands-On Irresistible Hors d'oeuvres on Saturday, December 10 at 10am
- Hands-On Holiday Cookie Boot Camp Saturday, December 17 at 10am
- Virtual Croquembouche Workshop Sunday, December 18 11am CST
- Hands-On Festive Family Baking Friday, December 23 10am
- Virtual Fondue Party Friday, December 30 6pm CST