Creamy roast onion and rosemary sauce

Preparation time less than 30 mins
Cooking time 30 mins to 1 hour

Ingredients

3 large onions, thickly sliced
50g/2oz butter
flaked sea salt and freshly ground black pepper
4 rosemary sprigs
450ml/¾ pint milk
2 tbsp cornflour mixed with 2 tbsp water

Method

1. Preheat the oven 200C/400F/Gas 6.
2. Place the onions in a medium-sized roasting tray with the butter and season with salt and pepper. Place in the oven for 40 minutes until cooked and beginning to go slightly golden, turning occasionally in the tray.
3. As soon as the onions are in the oven, place the rosemary in a saucepan with the milk. Gently bring to the boil, then remove from the heat. This allows the rosemary flavour to infuse into the milk.
4. Just before the onions are done, stir the cornflour mixture into the rosemary-infused milk. Place the pan back on to the heat and bring to a gentle simmer, cooking for a couple of minutes until thickened slightly.
Remove the rosemary and pour the sauce into a food processor or liquidizer.
5. Take the onions from the oven and add to the sauce. Blitz until smooth, season with salt and pepper and either serve straight away or gently reheat when needed.