French Onion Soup or Soupe a l’Oignon Gratinee de Trois Gourmandes [Onion Soup Gratineed de Luxe] from Mastering the Art of French Cooking by Julia Child et al.

This is one of the expansion/escalation “serving ideas” Julia shares that starts with the regular Soupe a l’Oignon, but a gratin version of onion soup is generally what we consider French Onion Soup (in that if I ordered French Onion Soup in a restaurant and it did not come with beautifully browned ooey-gooey melted cheese and toast layered on top, I would, like, I don’t know, cry maybe, or just be real sad.*

Julia says

The onions for an onion soup need a long, slow cooking in butter and oil, then a long slow simmering in stock for them to develop the deep, rich flavor which characterizes a perfect brew. 43 

So that’s what we’re gonna do.

I’m doing all of this in my Dutch oven. While some of the versions of this soup can be served in individual pots, as a French Onion Soup bowl, you really can’t do this version easily that way as you have to mix in some final ingredients, an additional enrichment Julia calls the “final fillip.” And my 2-quart Corningware says it’s not broiler-safe, so I’m using the Dutch oven.

The way Julia stacks these recipes is confusing in the cookbook because of all the variations, but in broad strokes for this version:

1)    Caramelize the onions
2)    Make the Soup
3)    Make the croutes
(Or stop here, see HINDSIGHT NOTE)
4)    Build the gratin
5)    Add the “final fillip” 

Go to the bottom for the full ingredient and equipment list. I’ll do this in stages here as it made the most sense to me. I’m not going to do this recipe like this again though, and I’ll put my thoughts and changes in sidebars and the “hindsight note” below.

1)    Caramelize the onions for the soup (allow 60-90 min):

1-1/2 lbs or about 5 cups of thinly sliced yellow onions
3 Tb butter
1 Tb oil 

1 tsp salt
¼ tsp sugar 

3 Tb flour

A heavy-bottomed, 4-quart (or larger) saucepan (or oven-safe Dutch oven).

Melt butter and oil in your saucepan over medium heat, add onions, then cover and cook for 15 minutes.

Uncover, lower heat as low as you can, add salt and sugar. Cook very gently for 60-90 minutes stirring occasionally for the first 45, then every 5-10 minutes until onions have reached a rich deep brown. Less time means slightly higher heat, but also watch more closely and stir more often. Be warned.**

Sprinkle in flour and stir for 3 minutes.

2)    Make the soup

Add all of the following to your onions:

Sidebar: I think this needs thyme. Add a large sprig or three here, and fish out before you build your gratin. Don’t gotta, but I will next time.

2 quarts boiling brown stock
½ cup dry white wine or dry white vermouth
Salt and pepper to taste 

Add 1-2 ladlefuls of your stock to your onions, deglazing the pan, scraping up all the fond that has accumulated on the bottom and loosening your onion and flour mixture. Then pour in the rest of your boiling stock and add the white wine to your onions.

Simmer, partially covered for 30-40 min. Taste for seasoning.

You can stop right here and just eat this and it’s delicious onion soup. Or…
You can add 3T of cognac before serving and it’s delicious onion soup with cognac in it. Or…

3)    Make the croutes:

12-16 slices French bread, cut 3/4” – 1” thick
Olive oil or beef drippings
1 cut clove of garlic

Sidebar: OK JULIA, STOP RIGHT THERE! We’re talking about 24-32 teaspoons of olive oil!!?? So 8-10+ Tablespoons. That’s 4-5 oz of olive oil!? Half a cup of olive oil?! For the toast?! The toast I’m gonna smother in cheese?

Sweet Charlie Brown!

I’m using way less, and you have my permission to do so as well, or put half a cup of olive oil on your bread, that’s fine, too. Do you.

Also, is the garlic rubbing strictly necessary? Probably not.

Preheat oven to 325-degrees. Place the bread in one layer in a roasting pan or on a baking sheet for 15 minutes (the bread will be in the oven for 30 minutes total, but you’re going to remove halfway through to brush with olive oil). Remove bread and then “each side may be basted with a teaspoon of olive oil or beef drippings” (44).

Bake 15 more minutes after your generous or otherwise “basting.”

Remove from oven, and rub each piece with garlic.

HINDSIGHT NOTE: Next time I make this, I’m going to stop here and proceed differently. I won’t gratin the dish at all. I’ll make the croutes as below, but broil briefly with the cheese to melt it on top of the bread on the baking tray, then serve the toast with the melted cheese atop the soup in each individual serving bowl.

If you are serving this for a party, and intend to serve all of it, go ahead and continue as Julia instructs. But here’s the thing: you have to sneak under the crust you make in step 4 to add the ingredients in step 5, but my crust didn’t “lift” that easily to allow me to add the final slurry of ingredients, and those ingredients include cornstarch, which thickens the soup quite a bit, and the bread soaks the soup up quite a bit, so it’s not conducive to leftovers like this. And it’s a lot of bread for this soup. (We had leftover bread with no accompanying soup to have it with.)

I would add the cognac and Worcestershire from step 5 here! (Don’t bother with egg and cornstarch—the soup is thick enough!) Make as many croutes as I intend to serve now, melt the cheese on top of them in the broiler, and add the now ooey-gooey toast to the top of the soup at serving time.

ALSO, next time I’ll double the soup recipe to just have leftover Onion Soup. Once you’re spending 3 hours making soup you may as well be able to have some for lunch or dinner the next day. Make it 3 lbs onions, and 4 quarts stock, or 2 quarts and a bottle of red wine. And you can always melt more cheese on toast to serve the next day. Or just eat delicious onion soup.

This is your make ahead point. You can set the soup and croutes aside here until ready to serve.

You can add cognac here, and just put the bread in the bottom of bowls and serve your onion soup just ladled over the top of it just like this and pass some grated cheese around the table. Or…

4)    Build the gratin:

Fireproof tureen, ovenproof casserole, or Dutch oven (needs to be able to be put under the broiler, not just in the oven)

Onion soup you made
1 T grated raw onion
2 oz Swiss cheese cut into very thin slivers
12-16 croutes you made
1-1/2 cups grated Swiss cheese, or a mixture of Swiss and Parmesan
1 Tb olive oil or melted butter

Preheat oven to 325-degrees. Bring the onion soup back up to a boil. Stir in the grated onion and the slivered cheese (super doesn’t matter if it’s slivered—it can just be grated like the rest of the cheese).

Float the croutes on top, and cover with the grated cheese. Sprinkle with the oil or melted butter.

Bake for 20 minutes, then remove, and preheat broiler, and broil 2 minutes more.

You can serve the soup now just like this or…

5)    The “final fillip” (45) aka that which makes it Onion Soup Gratineed de Luxe (and not just Gratineed)

A 2-quart bowl
1 tsp cornstarch
1 egg yolk
1 tsp Worcestershire sauce
3 Tb cognac 

Sidebar: This was not that easy, the lifting the crust part. Maybe I didn’t toast my bread enough, because it stated soaking up the soup almost immediately. And this really thickened the soup quite a bit because of the cornstarch. Next time I’m just going to try to stir in the cognac and Worcestershire sauce by themselves right before serving, and add the toast as described above. 

Combine cornstarch, egg yolk, Worcestershire sauce and cognac into the bowl, and whisk to combine. Just before serving the soup, lift up an edge of the crust with a carving fork, remove a ladleful of soup, and add to the egg mixture. Whisk together to combine, then add a couple more ladlefuls of soup. Stir together, then pour back into the soup under the crust, stir to combine, and serve.

* I started by saying I would throw it on the ground and walk out, but I’ve never so much as sent food back at a restaurant. Even when I got a beef burger when I was a vegetarian and I know I ordered a veggie burger, I just told the concerned waiter who was wondering why I was looking at my food all sad and shit that I just realized I was really full and I asked for a to-go container to take it home where I threw it away and made buttered noodles or like Morningstar Farms “chicken” nuggets or something.

**I disagree with Julia here on heat and timing. Julia says moderate heat for 30-40 minutes for the onions after the initial covered 15 minutes. You can get some decent color this way and much faster than my method, but it’s far too easy to burn your onions as you really need to stir CONSTANTLY at this kind of heat. And you cried too hard to slice a pound and a half of onions to ruin them now. So: Cook covered on moderate heat with butter and oil for 15 minutes, uncover, and just turn your burner down low, stir occasionally for the first 45 minutes, and then set yourself a timer for every 10 minutes to stir, scrape up the little browned bits and fond that accumulate at the bottom. When it starts getting close, you’ll want to stir every 5 minutes so they don’t start to get frizzled. Just take it the fuck easy on the heat. It’s a rainy day soup for a reason. Let it take some time.

Soupe Gratinee des Trois Gourmandes [Onion Soup Gratineed de Luxe] from Mastering the Art of French Cooking by Julia Child et al.

Ingredients

to make Soupe a l’Oignon [Onion Soup]

1-1/2 lbs or about 5 cups of thinly sliced yellow onions
3 Tb butter
1 Tb oil 
1 tsp salt
¼ tsp sugar
3 Tb flour
2 quarts boiling brown stock
½ cup dry white wine or dry white vermouth
Salt and pepper to taste 

to make Croutes [hard toasted French bread]

12-16 slices French bread, cut 3/4” – 1” thick
Olive oil or beef drippings
1 cut clove of garlic

to make Onion Soup Gratineed with Cheese

The onion soup you made
1 T grated raw onion
2 oz Swiss cheese cut into very thin slivers
12-16 croutes you made
1-1/2 cups grated Swiss cheese, or a mixture of Swiss and Parmesan
1 Tb olive oil or melted butter 

to make Onion Soup Gratineed de Luxe

1 tsp cornstarch
1 egg yolk
1 tsp Worcestershire sauce
3 Tb cognac

Equipment

A heavy-bottomed, 4-quart (or larger) saucepan (or oven-safe Dutch oven)
Cookie sheet or sheet cake pan
A wire whisk
A soup ladle
A serving fork
A 2 quart bowl
A wooden spatula or flat edge spoon  

Citation

Child, Julia, Louisette Bertholle, and Simone Beck. Mastering the Art of French Cooking. 1961. 40th Anniversary ed., Knopf, 2009.