Onion Gravy with Cornflour, No Roux

Cornflour behaves nothing like flour and it is worth understanding why. It has roughly twice the thickening power, it goes in at the end rather than the beginning, and it gives a translucent gloss instead of the slightly opaque finish a roux produces. It is also the simplest route to a gluten free gravy that nobody has to make allowances for.

Ingredients

Makes about 600ml, enough for six plates

• 3 large (about 500g / 1lb 2oz) brown onions sliced 4mm thick
• 30g (1oz) butter
• 1 tbsp rapeseed oil
• 1 tsp caster sugar
• 750ml (1⅓ pints) hot beef stock use a gluten free stock
• 1 tbsp tamari gluten free soy sauce
• 2½ tbsp cornflour slaked in 4 tbsp cold water
• salt and black pepper

Kit

• Saucepan
• Small bowl
• Wooden spoon

Method

1. Melt the butter with the oil in a saucepan over a medium low heat, add the onions and a pinch of salt, and cook for 30 minutes, stirring every few minutes, until deep brown and reduced right down.

2. Add the sugar and cook for 2 more minutes so it melts and deepens the colour further, scraping the base as you stir.

3. Pour in the hot stock and the tamari, scrape the base clean, and bring to a gentle simmer. With no roux in the pan the liquid stays thin at this stage, which is normal and correct.

4. Simmer uncovered for 12 minutes so the onion flavour gets right into the stock. Reduce it a little if you want, though the cornflour will do the thickening so this is about flavour rather than body.

5. Mix the cornflour with the cold water until there is no grit at the bottom of the bowl and it looks like single cream. Cornflour must go into cold water or it clumps instantly, which is the one way this recipe can go wrong.

6. With the gravy at a gentle simmer, pour in the slurry in a slow stream while stirring continuously. It thickens within about 30 seconds and turns visibly glossy.

7. Simmer for exactly 2 more minutes to cook out the starch, then take it off the heat. Do not keep boiling it hard, because prolonged violent boiling breaks cornflour down and the gravy thins again. Season and serve.

Tips worth knowing

• Cornflour is about twice as powerful as plain flour, so 2½ tablespoons here does the work of 5 tablespoons of flour.
• Add the slurry slowly and stop when it looks right. You can always add more, but you cannot take it out.
• A cornflour gravy sets more firmly in the fridge than a flour one and can look like jelly. It loosens perfectly on reheating, so do not panic.
• Check your stock. Cubes and liquid stocks very often contain wheat, and that is the only thing standing between this recipe and being reliably gluten free.

Keeping and reheating

Fridge for 4 days. It sets very firm when cold. Reheat gently with a splash of water, stirring until it becomes pourable again. It freezes for 3 months but comes back slightly thinner, so hold back a little of the slurry if you plan to freeze it.

Questions people ask