Mary Berry Onion Sauce Recipe

Name: Mary Berry Onion Sauce Recipe
Prep time: 10 min
Cook time: 25 min
Total time: 35 min
Ingredients: 2 large onions, finely sliced; 25g butter; 25g plain flour; 500ml whole milk; 1 bay leaf; 2 cloves; ½ tsp salt; ¼ tsp white pepper; 2 tbsp double cream (optional)

Mary Berry Onion Sauce is a classic British side dish that is smooth, creamy, and packed with gentle onion flavor. Traditionally served with roast chicken, turkey, gammon, or pork, this comforting sauce adds richness without overpowering the main dish. The texture is silky and velvety, while the flavor is mildly sweet from slowly cooked onions and creamy milk. This easy recipe takes about 35 minutes from start to finish, making it perfect for both Sunday roasts and holiday dinners.

Ingredients

For the Onion Sauce

2 large onions, finely sliced
25g butter
25g plain flour
500ml whole milk
1 bay leaf
2 cloves
½ teaspoon salt
¼ teaspoon white pepper
2 tablespoons double cream (optional)

How to Make Mary Berry Onion Sauce Recipe

Prepare the onions: Peel and finely slice the onions. Keep the slices thin so they soften evenly and blend beautifully into the sauce.
Cook the onions: Melt the butter in a medium saucepan over low heat. Add the sliced onions and cook gently for 8 to 10 minutes until soft and translucent. Do not allow them to brown.
Make the roux: Sprinkle the flour over the onions and stir continuously for 1 minute. This removes the raw flour taste and forms the base of the sauce.
Add the milk: Gradually pour in the milk while whisking constantly. Continue stirring until the mixture becomes smooth and lump-free.
Simmer gently: Add the bay leaf and cloves. Bring the sauce to a gentle simmer and cook for 15 minutes, stirring occasionally until thickened.
Season the sauce: Remove the bay leaf and cloves. Stir in the salt and white pepper.
Finish and serve: Stir in the double cream if using. Serve warm alongside roast meats, poultry, or festive dinners.

Tips for the Best Mary Berry Onion Sauce

How do I prevent lumps in onion sauce?

Add the milk gradually while whisking continuously. This creates a smooth and silky texture.

Can I make the sauce richer?

Yes. Stir in double cream at the end of cooking for a richer and more luxurious finish.

Why should onions not brown?

Keeping the onions pale gives the sauce its traditional mild flavor and creamy color.

Can I blend the sauce?

Yes. For an extra smooth texture, blend the finished sauce with a hand blender before serving.

Serving Suggestions

Serve with roast turkey.
Pair with roast chicken.
Enjoy alongside baked ham.
Serve with roast pork.
Add to Christmas dinner plates.
Spoon over mashed potatoes.

Storage

Room Temperature

Do not leave the sauce at room temperature for more than 2 hours.

Refrigerator

Store in an airtight container for up to 3 days. Reheat gently on the stovetop while stirring.

Freezing

Freeze in freezer-safe containers for up to 2 months. Thaw overnight in the refrigerator before reheating.

Nutrition

Calories: 120 kcal
Carbohydrates: 10g
Protein: 4g
Fat: 7g
Saturated Fat: 4g
Sodium: 260mg

Nutrition values are estimates and may vary depending on ingredients used.

FAQs

Can I make onion sauce in advance?

Yes, you can prepare it up to 2 days ahead and reheat gently before serving.

Can I use red onions instead of white onions?

Yes, although white or brown onions provide the traditional flavor and color.

How do I make the sauce thicker?

Simmer it a little longer or add a small amount of extra flour mixed with milk.

What meat goes best with onion sauce?

It pairs wonderfully with roast turkey, chicken, pork, and gammon.