Smoked French Onion Soup on the Grill - Indigo Pool Patio BBQ

Smoked French Onion Soup on the Grill

Smoked French Onion Soup on the Grill is a traditional and hearty soup made with beef marrow bones that have been smoked and roasted, then turned into a delicious bone broth. The broth is then added to a load of caramelized onions and turned into a soup.




Smoked Bone Broth 

  • 10 lbs. beef soup bones
  • 1 head garlic, top removed
  • Whiskey oak wood chunks or Brandy wood chunks
  • 28 cups (7 quarts) water
  • 2 carrots, chopped in half or thirds
  • 2 to 3 stalks celery
  • 1 onion, quartered

French Onion Soup

  • 2 tbsp. butter
  • 1 tbsp. oil
  • 3 to 4 cloves garlic, minced
  • 4 lbs. / 4 to 5 medium / 3 large onions, thinly sliced
  • 1 bay leaf
  • 4 sprigs fresh thyme
  • Salt and pepper to taste

To Serve

  • 1 French Baguette
  • Sliced or shredded Gruyère cheese
  • Sliced or shredded Emmental cheese


Smoked Bone Broth 

  1. The day before you want to have French onion soup. Blanch the bones for 20 minutes by covering them with cold water in a large stockpot, then bringing them to an aggressive simmer. Drain and set aside. This removes impurities.
  2. Fill the bed of a Napoleon Smoker Box with wood chips. Move the cooking grids out of the way on your grill and place the smoker box over the burner you plan on lighting. Replace the cooking grids. Preheat to between 350°F and 400°F using indirect heat.
  3. Place the blanched marrow bones upon a baking sheet with the head of garlic. For extra smoked flavor, add at least one of the onions to the tray too. Whole. Smoke-roast the bones and garlic for 30 to 45 minutes, turning the bones at least once. 
  4. Once the bones are satisfactorily smoke roasted, remove them from the barbecue. Place the bones into a stockpot and add enough water to cover them, roasted garlic, carrots, celery, and a quartered onion (not smoked). Gently simmer for 8 to 12 hours. This step is crucial to a delicious broth and can be done overnight or up to five days ahead of time.
  5. Once sufficiently simmered, strain the broth through a fine-mesh strainer, twice. Discard the bones and vegetables. Keep the clear broth. Place into a sealed container until needed. This can also be used as the base of any beef soup. It should become gelatinous when room temperature or cold. 

French Onion Soup

  1. Melt the butter and oil in a stockpot. Add the onions cooking over medium-low heat until caramelized *Do not rush this part. When they are nearly ready, add the garlic.
  2. Add the sherry to deglaze the pan. Once any brown bits have been scraped up, add the beef stock. 
  3. Create a sachet or bundle from the thyme and bay leaf. You can do this by tying it with butcher’s twine or wrapping them in some cheesecloth. 
  4. Bring the pot to a boil, then reduce to a simmer until the liquid has been reduced by 25% - about an hour. 
  5. When the soup is ready, preheat your oven broiler, or grill to high. Slice the baguette into rounds, toast the baguette rounds and divide the soup into bowls. Top the soup with one or two toasted baguette rounds, then a little of both kinds of cheese. Broil or grill until the cheese is melted and starting to brown. 
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