Preheat the oven to 220°C/200°C fan/gas mark 7.

Break the layers of the onion wedges apart a little and arrange on a baking tray. Drizzle with 2 tablespoons of the olive oil and roast for 20–30 minutes until the onion ‘petals’ are caramelised and charred at the edges.

While the onions roast, prepare the rest of the salad. Melt the butter in a large frying pan over a medium-high heat. 

Core the pears (no need to peel), and cut each one into 8 wedges, then fry the wedges for 5 minutes on each side until golden. In the last minute or so of cooking, add the walnuts to the pan, too, so they can soak up the buttery pear juices and get a little colour themselves. Remove from the heat and set aside.

For the dressing, put the vinegar, mustard, honey and a pinch of salt in a clean, screw-top jam jar and muddle together. 

Add the remaining 6 tablespoons of oil. Screw the lid on tight and give it a vigorous shake to combine the ingredients in a thick, satiny sauce. 

Check the balance of flavours – it should be sharp but sweet. Remember the blue cheese will bring a salty punch to the salad later, so go easy on the salt.

Separate the radicchio or chicory leaves and put them in a wide serving bowl. Pour over the dressing and toss gently to coat every leaf. Crumble over the blue cheese, then add the warm pears and walnuts, plus any juices from the pan. Finish with the roast onions and serve.