Onion Gravy with Wholegrain Mustard
Medium browned onions, a cider deglaze and two tablespoons of wholegrain mustard stirred in off the heat so the seeds keep their pop.
- Contains meat
- mustard
- cider
- gammon
- sausages
- sharp
- Prep
- 10 min
- Cook
- 40 min
- Total
- 50 min
- Serves
- 4
- Difficulty
- Easy
Mustard and onion is one of those pairings that works because they cancel out each other's excesses. The onions are sweet, the mustard is sharp, and the seeds give you a texture that a smooth gravy never has. Stir it in off the heat, because boiling wholegrain mustard flattens it into something dull and vaguely sour.
Ingredients
Makes about 500ml, enough for four plates
Scaled amounts are rounded to something you can actually measure. Season at the end and trust your mouth over the maths.
Kit
- Frying pan
- Whisk
Method
Heat the butter and oil in a frying pan over a medium low heat, add the onions with a pinch of salt and cook for 25 minutes, stirring every few minutes. Take them to a medium brown rather than the very dark end, because you want the mustard to be the loudest thing on the plate.
Pour in the cider and turn the heat up. Let it bubble for 4 to 5 minutes until it has reduced by about two thirds, scraping the base as it goes. The sharpness cooks off and what stays behind is apple sweetness.
Stir in the flour and cook for 2 minutes, keeping everything moving so the flour coats the onions evenly.
Add the hot stock in two goes, whisking after each until smooth, then bring to a simmer and cook for 10 minutes until it coats the back of a spoon.
Stir in the honey and check the balance. Cider and stock vary a lot, and the honey is there to round off any sourness rather than to sweeten it.
Take the pan off the heat and leave it for a minute so it stops simmering, then stir in the wholegrain mustard. Boiling mustard drives off its volatile heat and leaves a flat, slightly bitter taste, so this last step really does need to happen off the heat.
Season with salt and black pepper and serve straight away, while the seeds still have their pop.
Tips worth knowing
- If the gravy has to sit and be reheated, hold back half the mustard and stir it in at the last moment, because the first half will have gone soft.
- A mix of wholegrain and a teaspoon of Dijon gives you both the texture and a rounder background heat.
- For an alcohol free version, use 150ml of cloudy apple juice with a teaspoon of cider vinegar and reduce it the same way.
- This is the gravy for a gammon steak. It handles the salt and the fat better than anything sweeter.
Change it up
- Add 2 tablespoons of crème fraîche at the end for a creamy mustard sauce that suits pork chops and mash.
- Swap the honey for a teaspoon of maple syrup and use it over a hot dog or a sausage sandwich.
Keeping and reheating
Fridge for 3 days, freezer for 2 months. The mustard fades over time, so refresh it with an extra teaspoon stirred in after reheating.
Questions people ask
Should you add mustard to gravy before or after cooking?
After, and off the heat. The compounds that give mustard its heat and aroma are volatile and boil away quickly, so mustard added early just makes the gravy vaguely sour. Stir it in at the end and you keep the sharpness and the seeds keep their texture.
What goes with mustard onion gravy?
Gammon steaks, pork chops, bangers and mash, and a bacon chop. It is a great foil for salty, fatty meat. It is less good with beef or lamb, which tend to want something darker and less acidic.
Can I use English mustard instead?
Yes, but use only a teaspoon because English mustard is much hotter and has no seeds. You lose the texture that makes this recipe what it is, so it becomes a different, sharper gravy rather than the same one.