This soup is three ingredients doing everything, so each one has to be good: real broth, a bread that holds up, and gruyere that actually pulls. The technique is patience, deep slow caramelization of the onions until they go the color of dark toffee.
By Vince Gonzalez · Published July 2026 · Sourcing verified 5 Jul 2026
Prep15 min
Cook75 min
Makes4 servings
CuisineFrench
Cost$$$
Contains dairy · gluten
Make it gluten-free: swap in gluten-free versions of the wheat items (check the other labels too).
The Ingredients — and where to get them
Cook for4servings
Beef broth
A proper broth is the backbone here; thin stock makes thin soup.
Caramelize slowlyCook the sliced onions in butter over medium-low, stirring every few minutes, for 45 minutes. Don't rush the heat; you want them deep brown and jammy, not scorched.
DeglazeWhen the pot bottom is coated in brown fond, splash in a little water or wine and scrape it all up into the onions.
SimmerAdd the broth, bring to a simmer, and hold 20 minutes. Salt to taste now.
GratineeLadle into oven-safe bowls, float a slice of bread on each, pile on the gruyere, and broil until the cheese blisters and browns.
Can you make French Onion Soup in an air fryer? — Yes, with an insert
Not on its own — an air fryer can’t hold a pool of liquid. You can simmer it in an oven-safe dish or a silicone insert made to fit the basket, but the broth won’t reduce or brown the way it does on the stove, and that insert comes out scorching, so use oven mitts. For real depth, a pot on the stove wins.
Can you freeze French Onion Soup? — Yes
Yes — it freezes well. Cool it fully, portion into airtight containers, and it keeps a few months; thaw in the fridge and reheat gently.
Can you make French Onion Soup ahead of time? — Yes
Yes — it holds well and often tastes better the next day. Make it ahead and reheat gently before serving.
Is French Onion Soup gluten-free? — Not as written
Not as written — it contains gluten. Make it gluten-free: swap in gluten-free versions of the wheat items (check the other labels too).
Is French Onion Soup vegan? — No
No — it contains meat, so it isn’t vegetarian or vegan.
Community Notes
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