This bistro-style Mary Berry French Onion Soup Recipe is a masterclass in patience, relying on slowly caramelized onions to create a broth of incredible depth and sweetness. Topped with floating baguette toasts bubbling with melted Gruyère, it offers a luxurious, savory experience that brings the elegance of Paris straight to your kitchen table.
Mary Berry French Onion Soup Ingredients
The Soup Base:
- 50g (2 oz) Butter: Essential for the rich, nutty flavor of the onions.
- 1 tbsp Olive oil: Prevents the butter from burning during the long cook time.
- 1 kg (2 lb 4 oz) Onions: Thinly sliced. White or yellow onions work best for their balance of sweetness and astringency.
- 1 tsp Sugar: Helps kickstart the caramelization process.
- 2 cloves Garlic: Crushed.
- 1.5 litres (2 ¾ pints) Beef stock: A rich, dark beef stock is non-negotiable for the authentic color and savory depth.
- 300ml (½ pint) White wine: Dry white wine deglazes the pan and adds acidity.
The Cheesy Croûtes:
- 1 Baguette (French stick): Sliced into rounds.
- 175g (6 oz) Gruyère cheese: Grated. This Swiss cheese is the gold standard for melting without oiliness.
- 1 tsp Dijon mustard: Spread on the toasts for a hidden zing.
How To Make Mary Berry French Onion Soup
- Caramelize the Onions: Melt the butter and oil in a large, heavy-based saucepan over high heat. Add the sliced onions and sugar. Stir constantly for a few minutes until they start to brown. Reduce the heat to low, cover, and cook gently for 45 minutes. This slow “sweat” makes them incredibly soft.
- Deepen the Flavor: Remove the lid. Turn up the heat and cook for another 15-20 minutes, stirring frequently, until the onions are a deep, rich mahogany brown. Do not burn them, but do not be afraid of dark color—this is where the flavor lives. Add the garlic for the last minute.
- Deglaze and Simmer: Pour in the white wine. Turn up the heat and let it bubble vigorously to reduce by half. Pour in the beef stock. Bring to a boil, then reduce heat and simmer uncovered for 15-20 minutes. Season with salt and pepper.
- Prepare the Croûtes: While the soup simmers, toast the baguette slices on both sides under a hot grill (broiler). Spread one side of each toast thinly with Dijon mustard. Pile the grated Gruyère generously on top.
- Melt the Cheese: Place the cheese-topped toasts back under the grill until the cheese is bubbling, golden, and melted.
- Serve: Ladle the hot soup into bowls. Float one or two cheesy croûtes on top of each bowl (or serve on the side if you prefer them crisp). Serve immediately.
Recipe Tips
- Patience is Key: You cannot rush the onions. If you try to brown them too fast, they will be bitter. The 45-minute covered sweat followed by the open fry is Mary’s secret to sweetness.
- Stock Quality: Since this soup has so few ingredients, use the best quality beef stock you can find (or homemade). A weak stock cube will result in a weak soup.
- Mustard Trick: The smear of Dijon on the toast is a classic Mary Berry touch. It adds a subtle heat that cuts through the rich cheese and sweet onions.
- Cutting Onions: Slice the onions radially (from root to tip) rather than into rings. This helps them hold their shape better during the long cook.
What To Serve With French Onion Soup
- Green Salad: A sharp vinaigrette salad is essential to cleanse the palate.
- Red Wine: A glass of Pinot Noir or Merlot complements the beefy broth.
- Charcuterie: Serve as a starter before a meat and cheese board.
- Steak Frites: The ultimate French bistro menu pairing.
How To Store French Onion Soup
- Refrigerate: Store the soup (without the bread) in an airtight container for up to 3 days.
- Reheat: Bring the soup to a simmer on the stove. Make fresh cheese toasts just before serving.
- Freeze: The onion broth freezes beautifully for up to 3 months. Thaw overnight and reheat.
Mary Berry French Onion Soup Nutrition Facts
- Calories: 350 kcal
- Fat: 18g
- Carbohydrates: 25g
- Protein: 14g
- Sodium: 980mg
Nutrition information is estimated per serving with cheese toast.
FAQs
Yes, but the flavor profile will change significantly. To mimic the depth of beef stock, add a splash of soy sauce or mushroom ketchup to the vegetable stock.
In Mary’s method, you grill the toasts separately and float them on top, so you don’t need oven-safe bowls. If you want to broil the cheese on the soup, then yes, you need heat-proof ramekins.
The alcohol cooks off, leaving acidity and flavor. If you cannot use wine, substitute with 2 tablespoons of cider vinegar or sherry vinegar to balance the sweetness.
Mary Berry French Onion Soup Recipe
Description
A classic bistro soup featuring deeply caramelized onions in a rich beef broth, topped with mustard-laced cheesy toasts.
Ingredients
Instructions
- Sweat onions with butter/oil/sugar covered (45 mins).
- Brown onions uncovered (15-20 mins).
- Add garlic and wine; reduce by half.
- Add stock; simmer 15-20 mins.
- Grill baguette slices; spread with mustard.
- Top bread with cheese; grill until bubbly.
- Float toasts on hot soup.
Notes
- Slow cooking the onions is essential for sweetness.
- Use strong beef stock for color.
- Mustard adds a hidden kick to the toast.
- Freezes well without the bread.
