With caramelised red onion, walnuts and goat cheese.

I need to tell you before we start that the onion in this salad – a red onion, for both colour and flavour – is not lightly caramelised. It’s cooked to a state beyond that, until it completely collapses into an impossibly delicious mush. The liquid it produces, along with the oil in which it is cooked, form the basis of the salad’s dressing. And it takes a long time – about an hour – although you can make it well ahead and reheat it when required.

Both the onion and lentils can be prepared ahead of time. Keep them separate until assembling the salad, however, to stop the lentils softening too much.

This salad is loaded with flavours and textures: walnuts, goat cheese, fresh parsley, and a balsamic-heavy dressing which is thirstily soaked up by the lentils. All up, it's a punchy combination: not something you’d expect a lentil salad to be.

It’s terrific eating all by itself, and any leftovers are always my next day’s lunch. Because of the complexity of its flavours, the best way to use it as a side dish is against something simple. The way I serve it most often these days is alongside a steak, plainly grilled, with a sauce made by deglazing the pan with some lemon juice.

Warm lentil salad

For 2.

1 red onion
2 tablespoons olive oil
100g (½ cup) green lentils (Puy or French)
50g (⅓ cup) walnuts, chopped
50g (¼ cup) goat cheese
3 tablespoons parsley, roughly chopped

for the dressing:
1 tablespoon balsamic vinegar
1 tablespoon extra virgin olive oil
sea salt flakes
freshly ground black pepper

Peel, halve and finely slice the onion. Place in a dry, heavy-based pan over medium heat for 5 minutes, covered.

Add two tablespoons of ordinary olive oil and a good pinch of salt, stirring to coat the onion well. Take a sheet of baking paper and push it down into the pan to closely cover the onions. Cover the pan, turn the heat to very low and cook for 1 hour. The onions will collapse completely and will have thrown off their liquid into the oil.

If you are making the salad to eat now, keep the onions warm. If you're making it for later, you can take them off the heat and reheat when required.

Rinse and drain the lentils and cook in briskly boiling water for 10 minutes. Turn the heat to low and simmer, covered for 30 minutes. Drain and rinse under cool water.

Whisk the extra virgin olive oil and balsamic vinegar together in a small bowl. Season with salt and pepper.

Tip the lentils into the warm onions. Add half the dressing and toss everything together. The lentils will absorb the dressing – add a little more if you think the salad needs it. Add most of the walnuts and parsley, tossing again.

Transfer the salad to your serving dish. Crumble the goat cheese over, finishing with the remaining walnuts and parsley.