Boiled onions in cheese sauce

Prep Time: 0:20
Cook Time: 0:15
Serves: 4

Ingredients / Shopping List

500g onions
500ml milk
50g flour
50g butter
White pepper
1 tblsp mayonnaise
100g tasty cheddar

Prep to Cook:  Boiling pan, chopping board, vegetable knife, saucepan, wooden spoon, measuring jug, teaspoon, grater, colander


Peel the onions and cut each one in half.  

Slice each half into 6 wedges and place in pan. 
Cover with water, put lid on, boil gently for 10 minutes.
Drain the onions through colander and leave draining.
Prepare the sauce using the ‘roux method’.
Melt the butter and stir in the flour to create a paste.
Gradually add the milk and stir thoroughly to prevent lumps.
When all the milk is added, bring the sauce to the boil. 
Remove from the heat.
Dice half the cheese and add to the sauce.  
Add 1 tablespoon mayonnaise and season well.  Taste and adjust seasoning
Add the drained onions and stir well.
Grate the remainder of the cheese and sprinkle over the sauce and grill lightly to brown.


Check it out!

Boiled onions in sauce can be served on thick buttered toast or as a side to roast meat or chicken. Either way it tastes delicious. It costs very little and is always a winner.

Recipe Science

Cooks Know How:  Onions contain vitamin C,  a little potassium and calcium and are low calorie.  They contain flavenoids which are helpful to health.  Onions bring out the savoury flavour of foods and add texture and bulk.  The cells of onions need to be softened by boiling for this recipe.  Use just enough water to cover the onions and simmer gently.

The sauce is made with butter and plain flour, cooked first to make a paste, called a roux in the bottom of the pan.   Add a little milk at a time and beat the sauce using the back of the wooden spoon to keep it smooth.  It is essential to cook the flour whilst making the sauce.  The process is called gelatinisation.  It means the starch absorbs the liquid and bursts causing thickening.  The final temperature of the sauce is critical to the flavour.  It must boil to finalise the busting of the starch or it will taste ‘raw’.  Add the flavourings, the seasoning and the mayonnaise alongside the cheese. The cheese adds protein and helps to thicken the sauce.  Browning the dish by sprinkling with remaining grated cheese add colour and texture.