Creamy Onion Soup

Creamy onion soup is a silky pot of slowly caramelized yellow onions, butter, a little flour, broth, thyme and a splash of cream. The onions cook down until they are deep golden and sweet, then the broth and cream turn them into a smooth, spoonable soup. Serve it with garlic bread or toasted sourdough, and add croutons and shredded cheese at the table if you like. The onions are the whole point of the pot, so the rest of the ingredient list stays short and quiet.

Why You’ll Love This Creamy Onion Soup

• Deep onion flavor: the onions spend 30 to 40 minutes in butter until they are soft, golden and sweet, and that flavor carries through the whole pot.
• A simple pantry pot: butter, onions, flour, broth, thyme and cream are all you need besides salt and pepper.
• Easy to serve: ladle it into bowls and set out garlic bread or toasted sourdough, with croutons and shredded cheese on the side for anyone who wants them.
• A cold-day soup: it is rich without being heavy, it fills a bowl on a chilly evening, and it reheats well for lunch the next day.

What Is Creamy Onion Soup?

Creamy onion soup is a stovetop soup built on caramelized yellow onions. The onions are cooked slowly in butter, coated with a little flour, then simmered in broth with thyme and finished with cream. It is not a crock of French onion soup with croutons served under a layer of melted cheese. The cheese and croutons, if you use them, go on at the table so the soup stays creamy in the bowl. The finished pot is golden and creamy, with soft onion strips and thyme in every spoonful. Store leftovers in the refrigerator; see this FDA guide to storing food safely.

Ingredients for Creamy Onion Soup

• 4 tablespoons butter
• 4 large yellow onions, thinly sliced
• 2 tablespoons all-purpose flour
• 4 cups chicken broth, or vegetable broth
• 1 teaspoon fresh thyme leaves, plus more for serving
• 1/2 cup heavy cream
• 1/2 teaspoon salt, plus more to taste
• 1/4 teaspoon black pepper
• Garlic bread or toasted sourdough, for serving
• Optional: croutons and shredded cheese

Ingredient Notes

This is a classic creamy onion soup written to match a golden pot of caramelized onions finished with cream and thyme. All ingredients are generic, with no brand names.

• Butter: 4 tablespoons, enough to coat the onions as they cook down. Soft, even heat matters more than extra butter.
• Yellow onions: 4 large onions, thinly sliced. Yellow onions turn sweet and deep gold as they caramelize, which is what you see in the bowl.
• Flour: 2 tablespoons all-purpose flour, stirred in after the onions are golden. It gives the soup a little body so the cream can sit in a silky broth.
• Broth: 4 cups chicken broth, or vegetable broth if you want a meatless pot. A plain broth lets the onion flavor stay in front.
• Thyme: 1 teaspoon fresh thyme leaves in the pot, plus a little more on top of each bowl. Dried thyme also works; use about 1/2 teaspoon.
• Cream: 1/2 cup heavy cream, stirred in at the end. It rounds the soup without turning it into a heavy cream soup.
• Salt and black pepper: 1/2 teaspoon salt to start, plus 1/4 teaspoon black pepper. Taste at the end, because broths vary.
• For serving: garlic bread or toasted sourdough. Croutons and shredded cheese are optional and can be set out in small bowls.

How to Make Creamy Onion Soup

1. Caramelize the onions: melt the butter in a large pot over medium-low heat. Add the sliced onions and a pinch of the salt. Cook, stirring often, until the onions are deep golden, soft and sweet, 30 to 40 minutes. If they start to darken too fast, turn the heat down and add a splash of water to loosen the browned bits on the bottom of the pot. Those browned bits are full of flavor and should go back into the soup, not burn.
2. Add the flour: sprinkle in the flour and stir for 1 minute, until the onions are coated and the flour no longer looks raw.
3. Add the broth and thyme: slowly pour in the broth, stirring and scraping the bottom of the pot. Add the thyme, the remaining salt and the black pepper. Bring the pot to a gentle simmer.
4. Simmer: cook 10 to 15 minutes, until the soup has thickened slightly and the onions are very tender.
5. Finish with cream: stir in the cream and heat the creamy onion soup gently until it is hot. Do not let it boil hard. Taste and add a little more salt and pepper if needed.
6. Serve: ladle the soup into bowls. Top with a little fresh thyme, and add croutons and shredded cheese if you like. Serve with garlic bread or toasted sourdough.

Hands-on time is about 15 minutes, and cook time is about 45 to 55 minutes, most of it spent on the onions. The recipe serves about 6 generous hot bowls.

Tips for the Best Creamy Onion Soup

• Give the onions time: the flavor comes from a slow, even cook. Medium-low heat and frequent stirs keep the onions golden instead of scorched.
• Slice the onions thinly and evenly: even slices cook at the same pace and give the soup the soft ribbons you want in the bowl.
• Add the cream at the end: stir it in after the soup has simmered, then heat it gently. A hard boil can make the texture less smooth.
• Taste the salt at the end: broths vary, and the onions grow sweeter as they cook. A small adjustment at the end is better than salting heavily at the start.
• Set toppings out at the table: croutons stay crisper, and each person can add as much cheese as they like.

What to Serve With Creamy Onion Soup

Creamy onion soup sits well with no-knead garlic bread or a slice of toasted sourdough. A simple green salad on the side is enough if you want a fuller plate. For another creamy bowl on a cold evening, try easy creamy potato soup, slow cooker broccoli cheese soup, or creamy mushroom soup. Croutons and shredded cheese can go in the bowl or stay in small dishes on the table, so the soup stays silky until you eat it.

Variations

• Vegetable broth: use vegetable broth in place of chicken broth for a meatless pot. The onions, thyme and cream still carry the soup, and the color stays a warm gold.
• A lighter finish: use 1/4 cup cream instead of 1/2 cup if you want a thinner, more brothy bowl. The onions should still be fully caramelized.
• Dried thyme: if you do not have fresh thyme, use about 1/2 teaspoon dried thyme in the pot, and skip the fresh garnish or add a little chopped parsley.
• Smaller batch: halve every ingredient and use a medium pot. Start checking the onions a little early, because a smaller pot can brown faster.

Storage

Let leftover creamy onion soup cool, then store it in a covered container in the refrigerator. See the FDA storage guide linked above and this USDA guide to leftovers and food safety for general refrigeration advice. Reheat portions on the stove over medium-low heat, stirring now and then, until the soup is hot. If it has thickened, loosen it with a splash of broth. Do not leave the soup out for long. This soup can be frozen without the cream; stir in the cream after you reheat it, so the texture stays smooth.

FAQ

What is creamy onion soup?

Creamy onion soup is a stovetop soup of slowly caramelized yellow onions, butter, a little flour, broth, thyme and a splash of cream. It is served in a bowl, often with garlic bread or toasted sourdough, and optional croutons and shredded cheese.

How long does it take to caramelize the onions for creamy onion soup?

Plan on 30 to 40 minutes over medium-low heat, stirring often, until the onions are deep golden, soft and sweet. If they start to brown too fast, lower the heat and add a splash of water.

Can I make creamy onion soup ahead of time?

Yes. Cook the soup through the simmer step, cool it, and keep it covered in the refrigerator. Reheat it gently, then stir in the cream, taste for salt, and add the thyme garnish, croutons and cheese when you serve it.

What can I serve with creamy onion soup?

Garlic bread or toasted sourdough is the simplest pairing. A small green salad works on the side, and croutons and shredded cheese can be added at the table.

How should I store leftover creamy onion soup?

Cool the soup, then keep it in a covered container in the refrigerator. Reheat it until it is hot, and add a little broth if it has thickened. Follow the FDA and USDA storage guidance linked above, and do not leave the soup out for long.