There are a gazillion versions of French onion soup. I reviewed about seven different chefs' recipes to land on this version below. Some chefs use cognac, some use sherry, some use white wine, some use all three, some use red wine, some don’t use wine – you get the picture.
Because I’m a fan of garlic, I noted one version that used two garlic cloves. So, I included garlic, which added richness to the caramelized onion flavor. One chef used 10 onions and about 1/3 of the liquid below, but I don't want onion hash. I want onion soup. Most chefs's recipes recommended 5-8 onions and 8 cups of beef stock, so I went with the majority.
The addition of cognac is traditional, but if you don’t have it like I didn't, or you don’t want it, at least use dry sherry. I did add one cup of white wine because Ina Garten used it — heck, she also used sherry and cognac, a boozy version — but this tastes fine without wine or cognac. Just don’t skip the sherry. It adds a richness that would be missed.
Onions are so huge these days, I can’t say how many to buy, but you’ll need at least 5 large yellow onions. You’ll also need four soup crocs, a large Dutch oven or a large pot with a lid, a large baking sheet, and hot pads to handle the crocs after the toppings are broiled. You'll also need time, as well as thyme. Give yourself at least two hours before serving. Oh, an optional serving suggestion is: 1 loaf purchased garlic bread to bake in foil while the soup simmers.
Recipe: French Onion Soup with Less-Sodium Tips
1/4 stick (2 T.) unsalted butter
2 T. olive oil
10 cups thinly sliced, large peeled yellow onions (depending on onion size, this can be 5 or more.)
Salt (or Low-Salt or No Salt) to your taste or preference
1/2 tsp. freshly cracked black pepper
2 cloves garlic, pressed or crushed
1 tablespoon all-purpose flour
1/2 cup dry sherry or cognac
1 cup dry white wine
8 cups beef stock (for less sodium, use Kitchen Basics No Salt)
2 bay leaves
1 tsp. fresh thyme leaves, or ½ tsp. dried thyme leaves
1/2 to 3/4 pound shredded Gruyere cheese
1 loaf French bread in 1-inch slices, OR use a French baguette, but you might need two per crock
1. Prepare the onions. Slice in half, root to stem, then peel off skin and tough outer layer. Place face down, then peel the remaining onions. After all are prepped, thinly slice all at once.
2. In a large pot or Dutch oven, melt the butter over medium heat and add the oil.
3. Add all sliced onions. Season with 1/2 tsp. of salt (or Low-Salt or No Salt). Stir, lift, and turn gently until onions begin to brown. Reduce heat to keep onions from browning too quickly. This should be a slow sizzle. Continue to stir, lift, and turn gently, for about 30 minutes until onions are a rich dark caramel color.
4. Add the crushed garlic and sweat for about a minute.
5. Add the flour and cook/stir for 2 minutes.
6. Add the sherry or the cognac, and the white wine if using, then cook, stirring for a few minutes.
7. Add the beef stock, 2 bay leaves, thyme, and black pepper, then bring to a low simmer. Cover and simmer for about 45 minutes.
8. While the soup cooks, slice the French bread into 1-inch slices. (One trick Alton Brown recommends in a video is to slice the bread, then use the face of your crock to cut a shape that fits.) If using a smaller French baguette, you may need two slices per crock.
9. Grate the cheese.
10. Preheat the broiler to toast the bread and finish the soup.
11. Place bread slices on baking sheet. Under the broiler, toast bread golden on one side. This happens quickly, so watch closely. Turn and lightly toast other side, then take bread out to cool.
12. Taste the soup and adjust seasoning with salt (or Low-Salt or No Salt) and pepper as needed. Remove the bay leaves.
13. Ladle the soup into 4 soup crocks. Cover each crock with toasted slice of French bread, then top with a mound of shredded cheese.
14. Transfer the crocks to the baking sheet and place under broiler until the cheese bubbles and browns. Don’t be surprised if the soup bubbles and spurts.
15. Serve with the remaining French bread slices, which you may want to toast.
16. Another option is to heat a store-bought loaf of garlic bread in foil while the soup simmers. Then serve the garlic bread with your soup, instead of plain bread or toast.