RealGravy

Onion Gravies

Balsamic Onion Gravy

Onions browned hard in olive oil, balsamic vinegar reduced right down to a syrup before the stock goes in, and no flour anywhere near it.

  • Contains meat
  • Dairy free
  • balsamic
  • no flour
  • lamb
  • sweet and sour
  • reduction
Illustration of Balsamic Onion Gravy
Prep
10 min
Cook
40 min
Total
50 min
Serves
4
Difficulty
Easy

Balsamic can go two ways in a gravy. Splashed in at the end it tastes raw and sour, but boiled down to a syrup first it turns sweet, thick and almost treacly. That second version is what this recipe is after. It is dark, glossy and slightly sweet sour, and it is very good with roast lamb or a plate of sausages that need waking up.

Ingredients

Makes about 400ml, enough for four plates

Scale

Kit

  • Heavy frying pan
  • Small saucepan

Method

  1. Heat the oil in a heavy frying pan over a medium heat and add the onions with a pinch of salt. Let them sizzle properly. This gravy wants a firmer, hotter cook than the classic, because the balsamic brings the sweetness so the onions can bring the colour.

  2. Cook for 25 minutes, stirring every 2 minutes and scraping the base. The edges of the onions will go dark, almost singed in places, and that slight bitterness is exactly what balances the vinegar later.

  3. While that happens, put the balsamic and honey in a small pan and boil it over a medium heat for 4 to 5 minutes, until it has reduced by half and coats the back of a spoon like a loose syrup. Watch it, because it goes from syrup to burnt sugar quickly.

  4. Pour the balsamic syrup into the onions and stir for 2 minutes. It will go sticky and glue the onions together, and the pan will smell sharp for a moment before it settles.

  5. Add the hot stock and the rosemary sprig, bring to a brisk simmer, and reduce uncovered for 15 to 18 minutes until it has come down by about a third and thickened enough to leave a trail behind the spoon.

  6. Pull out the rosemary, taste and season. It should read savoury first with the sweetness arriving second. If the sweetness is winning, a small splash of stock and 2 more minutes of reduction sorts it.

Tips worth knowing

  • Reducing the balsamic separately is the whole point. Poured in raw it tastes acrid and dominates everything.
  • Cheap balsamic is often already sweetened, so taste yours before you add the honey and skip it if it is syrupy to start with.
  • This one reduces to a glaze if you keep going, which is a fine thing to brush over lamb chops in the last minute of cooking.
  • Do not use a non stick pan for this. You want the sticky brown film that a stainless or cast iron pan gives you.

Change it up

  • Use red onions and add a strip of orange peel with the stock for something that suits duck.
  • Swap the rosemary for two crushed juniper berries and serve it with venison sausages.

Keeping and reheating

Fridge for 5 days, and the acidity means it keeps well. Freezes for 3 months. Reheat gently, adding a splash of water if it has tightened up.

Questions people ask

Is balsamic gravy too sweet for a roast dinner?

It can be if you overdo the honey. Made as written it lands sweet sour rather than sweet, and it works well with lamb, sausages and roast root vegetables. For roast beef or chicken, a classic brown onion gravy is a better fit.

Can I use balsamic glaze instead of vinegar?

Yes, and you can skip the reduction step, but use only about 3 tablespoons because glaze is already concentrated and usually sweetened. Add it with the stock rather than before it.

Why is my gravy thin without flour?

Reduction is doing the thickening here, so it needs time. If after 20 minutes of hard simmering it is still watery, your stock is probably a weak cube mix with little body. Carry on reducing, or cheat with a teaspoon of cornflour slaked in cold water.