Creamy Onion Soup Twist
By Emma
Certified Culinary Professional
•
Recipe tested & approved
Caramelized yellow onions simmered in chicken broth, finished with creamy oat milk and a splash of dry sherry. Thickened with cornstarch instead of flour for a silkier texture. Toasted sourdough slices topped with Gruyère cheese, broiled until bubbling and golden. A cozy soup with robust depth, nutty cheese crunch, and that irresistible onion sweetness.
Prep:
25 min
Cook:
50 min
Total:
Servings:
4 to 6 servings
#French-inspired
#onion soup
#vegetarian option
#comfort food
#easy soup
Onions. Not just something to make you cry. I’ve tossed these into butter, watched them slowly turn that perfect copper, sweet and sticky almost like candy. Skip the rush, don’t stir obsessively but keep notes on textures and aromas. Heard a tip once—replace flour with cornstarch for silkier soups. Tried it. Better mouthfeel, less gummy. And sherry instead of brandy gives it a wild, dark edge—sherry’s got a bite that fades into background sweet. Bread? Not just bread. Sourdough for crunch and tang that pushes against melty nutty Gruyère dome. Broil it just right. Too much and it’s acrid, too little and you miss that golden crust. Soup thick but not glue. Complex but cozy. The magic of smell, texture, sound of bubbling bubbling—the real pulse of kitchen life.
Ingredients
- 2 liters (8 cups) thinly sliced yellow onions about 900 g
- 40 ml (2 1/2 tablespoons) unsalted butter
- 30 ml (2 tablespoons) dry sherry
- 15 ml (1 tablespoon) cornstarch
- 1 liter (4 cups) chicken broth
- 250 ml (1 cup) oat milk
- Salt and freshly ground black pepper
- 4 thick slices rustic sourdough bread lightly toasted
- 250 ml (1 cup) grated Gruyère cheese
About the ingredients
Onions are the soul here—pick firm, fresh ones with tight skins. The quantity is close but reduced a bit so it won’t swamp you. Butter measured but use unsalted, or it changes flavor balance. Sherry stands in for brandy—both add something different so pick your poison. Cornstarch instead of standard flour for thickening lets soup stay luxuriously smooth. Broth you want good quality—homemade or low sodium so you control salt later. Oat milk because dairy sometimes overpowers subtle onion taste and can curdle at hotter temps; plus, creaminess without heaviness is a modern twist. Rustic sourdough bread screams ‘bayou comfort’ here but French baguette slices work in a pinch. Gruyère chosen for its melting and flavor profile but Emmental or even fontina shine too. Toast bread first to avoid mush; cheese on top gets that sweet golden layer under broiler. Often people skip broil—which is a mistake, it’s the crescendo.
Method
Soup
- 1. Melt butter on medium heat in a large pot. Add onions, stirring every few minutes. Let them soften, turning translucent and soft—takes about 12 minutes. Then crank heat to medium-high. Stir often until deep golden and fringed with brown patches; caramelizing is slow but crucial. Watch closely to avoid burning. It’ll smell sweet, almost jammy—stop there.
- 2. Pour in dry sherry. It should hiss, bubble, evaporate almost totally. Scrape bottom to loosen fond for flavor. Sprinkle cornstarch all over, stir well for 1-2 minutes so no lumps remain—this thickens gently later, no more clumps like raw flour can cause.
- 3. Pour in chicken broth all at once. Raise heat to bring to consistent simmer. Let it bubble gently for 20 minutes, lid off. Soup should reduce slightly, smell rich with caramel and wine. Taste and season with salt and black pepper sparingly. At end, stir in oat milk for creaminess but no dairy heaviness.
Cheese Croutons
- 4. Preheat oven's broiler to high. Position rack near top but safe enough you won’t scorch bread instantly.
- 5. Arrange toasted sourdough on a baking sheet. Heap grated Gruyère evenly on each. Pop under broiler. Watch constantly—3 to 5 minutes tops. Cheese will bubble wildly, then brown and crisp at edges is goal. Remove before it burns bitter.
- 6. Ladle hot soup into bowls. Slap on cheesy croutons floating atop. Can break them up or dunk—preference. The cheese melts into soup with each scoop, mingling nutty, creamy, caramelized onion notes. Absolutely earthy aromas fill kitchen now.
Tips and Tricks
- Onions—your patience with slow caramelization makes all difference. If rushing, onions stay sharp and raw tasting.
- Sherry can swap with dry white wine or brandy but must evaporate completely to avoid harsh alcohol bite.
- Using cornstarch is subtle thickening; if using flour, cook longer to avoid pasty taste.
- Oat milk chosen for texture and mild sweetness; whole milk or half and half works but heavier.
- Bread must be crusty, firm enough to hold cheese and soak little soup without collapsing.
- Gruyère over cheddar here for melt quality and nuttiness—Swiss or Emmental can work in pinch.
- Watch the broiler obsessively or cheese crisps too fast and tastes burnt, not caramelized.
- If no broiler, use highest oven temp and toast under grill element but timing longer, check often.
Cooking tips
Start with patience—onions don’t hurry their deepening flavor. Medium heat for softening is key; louder sizzle signals raise temp. Caramelization is rewarded by smell first: you’ll notice sweet, almost toasted notes with slight bitter edges when it’s done. Sherry is added at peak caramel to lift flavor depth and deglaze pan fond—scrape or you lose what you cooked. Cornstarch sprinkled evenly prevents lumps, cook it enough so starch flavor disappears but doesn’t thicken too early. Low simmer afterward for blending and slight reduction. Final oat milk swirl at end cools soup slightly and boosts creamy feel—avoid high heat now or milk irritates. Croutons get treated carefully: bread toasted first to stay firm, broiled with cheese until bubbling and browned is all about timing and vigilance. Don’t wander, or end with blackened cheese. Serve immediately for contrast of hot soup and crunchy cheesy top. Pro tip: leftovers reheat well but crispiness lost, add fresh toast next day.
Chef's notes
- 💡 Onion caramelization needs slow heat. Start medium; onions soften, turn translucent before color shifts; smell cues sweet jammy notes. Push past light gold for rich depth but watch close or bitter spots appear. Don’t rush, avoid stirring nonstop or it turns mushy. If it smells burnt, pull back heat fast.
- 💡 Sherry hits pan at peak caramel. Listen for hiss, bubbles, quick evaporation. Scrape fond – key flavor here not to lose. Dry white wine works but evaporate fully; leftover alcohol bites hard. Brandy adds different note but same rules apply. Sizzle means heat too low or too high missing point.
- 💡 Cornstarch sprinkled evenly to avoid lumps. Stir 1-2 minutes, no more or thick comes early; flavor raw starch loses in heat. Flour possible if cooked extra long but texture heavier, pasty risk. Cornstarch keeps soup silkier, lighter mouthfeel. Add liquid gradually then simmer low for reduction.
- 💡 Broil cheese croutons carefully. Rack close but safe, watch constantly. Cheese bubbles wildly then crisps edges; remove before bitter burnt taste. Oven grill a fallback but timing longer, eyes open. Toast bread first to firm it; soggy croutons ruin texture contrast in bowl.
- 💡 Oat milk beats dairy here; subtle sweetness, keeps texture light. Whole milk or half and half add richness but risk curdling if too hot. Add oat milk last, off heat or low simmer, swirl gently. Avoid high heat now or milk splits; creamy feel without dairy weight.
Common questions
How do I know onions are caramelized?
Wait for color shift; strong sweet aroma. Brown patches, jammy smell. Avoid raw sharp taste. If they smell bitter, too far. Time roughly 12 minutes medium. Stir less, feel textures sticky but not mushy.
Can I substitute sherry with wine or brandy?
Yes, dry white wine or brandy okay. Must evaporate completely. Watch pan for bubbling, steam off alcohol. Partial evaporation means harsh alcohol bite remains. Flavor differs so pick what fits dish mood. Deglaze pan with liquid hot.
What if soup is lumpy after adding cornstarch?
Clumps mean uneven stirring. Sprinkle cornstarch slow, stir vigorously but brief. If lumps appear, strain. Wait 1-2 minutes cooking to dissolve starch flavor. Use small bowl mix starch with bit broth first if worried.
How to best store leftover soup and croutons?
Soup refrigerate in airtight container 3-4 days. Reheat low to avoid oat milk splitting. Croutons keep separate, wrap airtight or freeze, toast again before serving. Mix fresh bread if croutons soggy. Reheat soup slowly, stir often to maintain texture.
