Place the chillies and peppers over a hot barbecue, in a griddle pan or on a tray under a hot grill, turning them now and then until blackened and blistered all over.
Carefully lift the hot peppers and chillies into a bowl and cover tightly with clingfilm. As they cool down, they’ll cook gently in their own steam.
When cool enough to handle, peel the skin off easily, trim off the stalks, and scoop out the seeds.
Finely chop the peppers and chillies by hand or in a food processor and put to one side.
Peel and roughly chop the onions, then pick and finely chop the rosemary leaves.
Drizzle a splash of oil into a pan over a low heat, add the onions, rosemary, bay leaves, and cinnamon, then season with a little sea salt and black pepper.
Cook very slowly for about 20 minutes, or until the onions become rich, golden and sticky.
Add the chopped peppers and chillies, sugar, and balsamic to the onions and keep cooking until the liquid reduces and you’re left with a lovely thick sticky chutney.
Season well to taste, then remove the cinnamon stick and the bay leaves.
Spoon into sterilised jars and put them in a cool dark place, or keep in the fridge and use right away.
