Why it works: Potato and onion match in chemistry and in kitchens. They rank in the top 2% of all ingredient pairs, and 9,019 recipes mention both. Both carry 2-isopropyl-3-methoxypyrazine, which smells earthy, pea. The science ↓
The recipe
Ingredients
Contains: milk, wheat, soy (auto-detected from the ingredients and method; we can miss things, so check labels)
Directions
Roast the vegetables
Preheat oven to 400°F.
Place potatoes in large bowl.
Snip root end off each onion and cut each half into 3 sections.
Add onions to potatoes, breaking up onions with your fingers to separate.
Drizzle vegetables with oil, add thyme and toss well.
Spread vegetables on baking sheet.
Season with salt and pepper.
Slice top third off head of garlic and place it on a piece of foil.
Put 1/2 tablespoon butter on top of garlic and drizzle 2 teaspoons water onto foil.
Fold sides of foil to enclose; place on pan with vegetables.
Roast vegetables 45 minutes, then remove garlic.
Continue roasting vegetables until tender, about 15 minutes more.
Puree and thicken
In large saucepan, bring broth to a simmer over medium-low heat.
Transfer half the roasted vegetables to food processor and add 1/2 cup hot broth.
Process mixture until fairly smooth, then transfer to bowl.
Repeat with remaining vegetables and a little more hot broth, squeezing garlic pulp out of husks into last batch.
Stir all pureed mixture into broth in pan; keep pan over low heat.
In small saucepan, melt remaining 2 tablespoons butter over medium-low heat.
Add flour and cook, stirring constantly, 1 1/2 minutes.
Stir in milk and cook, stirring often, until thickened, about 3 minutes.
Stir in ladleful of soup and cook 1 minute.
Add mixture back to soup.
Cook over medium-low heat until heated through, stirring occasionally, about 10 minutes.
Serve
Serve right away, or cool, refrigerate and reheat when needed.
This recipe comes from the Recipes Wiki on Fandom and is licensed CC BY-SA 4.0. Our formatting and summaries are shared under the same licence.
Steps grouped into stages for easier reading; the method is the source's own.
Explore the science
The flavor team
The pairs that carry this dish. Each one is judged two ways: how much aroma chemistry they share, and how many recipes mention both.
-
Potato + oniontop 2% of all pairsAroma overlapstrongMentioned together9,019 recipes
Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
-
Onion + garlictop 1% of all pairsAroma overlapstrongMentioned together29,030 recipes
Shared aroma: furaneol (caramel, strawberry).
-
Olive + garlictop 3% of all pairsAroma overlapmoderateMentioned together23,449 recipes
Shared aroma: linalool (floral, citrus).
-
Potato + garlictop 3% of all pairsAroma overlapstrongMentioned together4,512 recipes
Shared aroma: furaneol (caramel, strawberry).
-
Butter + milktop 3% of all pairsAroma overlapstrongMentioned together81,222 recipes
Shared aroma: (z)-4-heptenal (biscuit, cream).
Ranks compare each pair with 20,000 random ingredient pairs on CompKitchen. How we score pairs
What each ingredient does
- Potatoes
- Break down into a smooth, starchy body that gives the soup its thickness.
- Onions
- Caramelize during roasting, adding sweetness and savory depth to the soup.
- Garlic
- Roasts soft and mellow, adding a sweet, nutty aroma to the puree.
- Olive oil
- Carries heat across the vegetables and helps them brown in the oven.
- Butter
- Adds richness and flavor, and with flour forms the base that thickens the soup.
- All-purpose flour
- Thickens the milk mixture into a roux that gives the soup body.
The step that matters
Cook the flour and butter before adding milk. Cooking the flour in melted butter for a minute and a half removes its raw taste and lets it thicken evenly. Adding milk to raw flour can leave lumps and a pasty flavor.
Flavor stand-ins for the thyme
How well each one fits the dish's main ingredients (potato, onion, olive, garlic, butter, flour, milk):
- Thymethe original
- Parsleyabout as good a flavor fit
- Rosemaryabout as good a flavor fit
Fit is the average pairing score against potato, onion, olive, garlic, butter, flour, milk. Candidates are from the same food group and used in at least 100 recipes. This compares flavor only: it does not check the job the ingredient does in the dish (bulk, moisture, acidity, structure).
“What each ingredient does” and “The step that matters” were written by Claude from this recipe’s own method and reviewed in samples by CompKitchen.
You might also like
Illustration
Illustration
Illustration
IllustrationThe Sunday pairing: one pairing, the chemistry behind it, and how to cook it. No spam, unsubscribe anytime.
Prefer an account? Create a free account for sign-in; Pro adds the full results and chemistry.