Grilled French Onion Soup

French Onion Soup (shutterstock)

When a friend asked me if I could create a hearty fall soup that begins on the grill, at first I was stumped.

I love making grilled gazpacho; it’s a regular in my summer rotation. But a cold tomato soup hardly is fit for fall. So I started thinking about my favourite soups, wondering which one would benefit from some time on the grill. All of the sudden, it came to me — French onion soup! French onion soup is my favourite meal in a bowl. It is the first thing I eat when I find myself in Paris and I order it whenever I see it on a restaurant menu.

But up until now, I never have been happy with the versions I made at home. With this new grilled recipe, all that has changed! I no longer need to cross the pond to have a great soup.

The soup is all about the broth, but I rarely have homemade beef stock on hand, so I needed to create a version that would compensate for using a boxed broth. I started by making one of my signature side dishes, “forgotten onions.” Forgotten onions are onions that are grilled (and forgotten) over indirect heat in their papery skins until they are deeply caramelized and almost collapse in on themselves.

This slow grill-roasting intensifies all the sweetness in the onions and eliminates the sharpness, making them something you will want to eat like a baked potato. To this, I decided to add roasted garlic to increase the depth of flavour of the broth.

Once the onions and the garlic are grilled, the soup comes together quickly. The peeled onions are sauteed in a little butter and “melt” into small pieces. The sweet roasted garlic mixes with the caramelized onions to create a rich base for the soup. Add the beef broth and full-bodied red wine and that’s almost all there is to it! But be forewarned, as simple as this soup is, the smell of it simmering on the stove will bring everyone running to the kitchen. It smells that good!

The key to this soup is to make it a day ahead to give the flavours time to truly meld. This soup also can be frozen and reheated, adding the bread and the cheese topping just before serving.

GRILLED FRENCH ONION SOUP

Start to finish: 3 hours active (30 minutes active)
Servings: 8

3 large heads of garlic
Olive oil
Kosher salt
4-pound bag sweet onions (7 to 8 large), not peeled
3 tablespoons unsalted butter
1 quart beef stock
2 cups red wine
1 1/2 tablespoons packed brown sugar
Generous pinch of white pepper, plus more to taste
8 thick slices of French bread, left out to get stale or dried in the oven
1 pound grated Gruyere or comte cheese

Prepare a grill for medium heat, indirect cooking. For a charcoal grill, this means banking the hot coals to one side of the grill and cooking on the other side. For a gas grill, this means turning off one or more burners to create a cooler side, then cooking on that side.

Remove the first layer of papery skin from each head of garlic. Slice off the top 1/2 inch from the top of each head. Set each head on a large square of foil, then drizzle with oil and sprinkle with salt. Loosely wrap the foil up around the garlic, crimping it to seal. Set on the cooler side of the grill. Add the onions to the same side of the grill. Cover the grill.

Cook the garlic for 40 to 60 minutes, or until the cloves are golden brown and soft. Grill the onions for 60 to 90 minutes, or until the skins are dark and the sugars have caramelized and blackened. When the garlic is cooked, remove from the grill and cool. Open the packets and squeeze the cloves from the skins and into a small bowl. When the onions are cooked, remove from the grill and set aside to cool for 15 minutes.

Meanwhile, in a heavy 6-quart stock pot over medium heat, melt the butter. Trim the ends off the onions, then peel and remove the outer skins. Chop each into large pieces, then add to the butter. Saute for 5 minutes, stirring occasionally. Add the reserved roasted garlic and about 1 teaspoon of salt. Stir well to combine, then cook for an additional 3 minutes, or until well mixed. The onions will separate into small pieces and look almost melted.

Add the beef stock, red wine, brown sugar and pepper. Bring to a boil, then reduce heat and simmer for 30 minutes. Taste and adjust seasonings.

Let cool, then refrigerate. The next day, bring soup to a boil for 5 minutes before serving, stirring occasionally. Taste and adjust seasonings if necessary.

Just before serving, heat the oven to broil.

Ladle the soup into oven-safe mugs or bowls about three-quarters of the way full. Place a piece of the stale bread on top of each serving, then top that with a generous handful of the cheese. Place the soup bowls on a baking sheet and place on the oven’s bottom shelf and cook for 2 to 3 minutes, or until brown and bubbly. Enjoy immediately.

Elizabeth Karmel is a barbecue and Southern foods expert. She is the chef and pitmaster at online retailer CarolinaCueToGo.com and author of three books, including “Taming the Flame.”