It took Mrs J three hours to make this sauce. One of which she spent on the treadmill, one in the bath and 30 minutes watching TV.

She cried while peeling the onions though. That counts for something, surely?

The good thing about this sauce is that it’s really smooth and creamy, without adding any cream. Just forget you added that lump of butter at the beginning and it’s positively slimming.

Also, it tastes really good with a nice piece of steak.

Here’s how you make it.

Put a couple of sprigs of thyme, a couple of bay leaves and 1 tsp of peppercorns in a little tied up cloth bag or a closed tea sieve.

In a medium saucepan, melt 60g of butter.

Add four medium-large sliced onions, 2 big cloves of garlic (roughly chopped) and one medium potato (cut into little cubes) to the butter. Stir fry over moderate heat for a few minutes. Try to get some colour into the onions (without burning them).

Reduce the heat to low and add two tbsp of water and a pinch of cayenne pepper. Get your bundle of herbs into the cooking liquid, cover and cook until the onions are very soft. This will take about 2 hours.

Drain the onions in a sieve, reserving the cooking liquid. Throw out the herb bundle.

Transfer the vegetables to ye olde faithful mixer and puree with 2 tablespoons of the cooking liquid and 3 tsp of balsamic vinegar. (Be careful with that hot puree in the mixer!)

If you’re feeling chefy, pass the puree through a sieve afterwards. Season with salt and freshly ground black pepper.

Serve with a good piece of steak.

If you need to reheat the sauce, make sure you do so on low heat.

Bon appetit!