BBQ Portobello Burger with Caramelised Onions and Saint Agur Cheese

Ingredients

4 grilled and steamed spring onions
600g Portobello mushrooms
Rapeseed or peanut oil for frying
2 finely chopped garlic cloves
1 Tbs butter
100g day-old sourdough bread, finely chopped
300mL BBQ sauce
2 eggs

Caramelised onions:

2 onions
2 Tbs butter
1 Tbs red wine vinegar

To serve:

120g Saint Agur or other creamy blue cheese
6 burger buns
Butter for buns
Finely chopped fresh chives – preferably garlic chives with flowers

Method

To grill and steam the spring onions, pour the oil into a ziplock bag big enough to accommodate the onions and sprinkle with salt and pepper. Put the bag next to the barbeque so it is close at hand. Light the barbeque and lay the onions on the grid while the charcoal is still actively flaming. Cook all over so the surface gets a little burnt.

Using tongs, transfer the onions into the ziplock bag and seal, shaking so the oil covers everything and leave for about 20 minutes so they steam.

Cut the mushrooms into 5mm cubes. Heat the oil in a frying pan or skillet over a high heat until it starts to smoke. Add the mushrooms and fry until they take on colour – about 10-15 minutes.

Chop the steamed spring onions and add with garlic to the mushrooms in the pan. Add butter, reduce the heat to medium and cook for a few minutes, stirring.

Remove pan from heat and allow to cool a little. Then add the bread, BBQ sauce and eggs. Stir so everything is well combined.

Take a handful of mixture at a time and shape into six round patties, either by hand or using a food ring. Put the patties in the fridge for at least an hour, preferably longer, so they hold together when you fry them.

Peel and chop the onions for the caramelised onion mix. Put onions and butter into a cold saucepan and cook over a medium heat with the lid on. The onions will start to release liquid and the flavours will be concentrated as a result of them cooking in their own juices. Stir with a wooden spoon about once every five minutes for about 30-40 minutes. Check they are not burning and if they get too dry, add vinegar earlier.

Pour on vinegar, increase the heat and cook for about 15 minutes, stirring until considerably reduced. Put to one side.

Heat a few tablespoons of oil in a pan over a medium heat. Fry the patties for a few minutes on both sides until they develop nice colour and a crispy surface. Transfer to an oven-proof dish and grill in the oven for 5-10 minutes.

Put a little cheese on each patty and cook for a little longer in the oven, until it melts.

Butter the buns on the cut surface, fry quickly in a pan or grill in the oven.

Place a patty on the bottom of each bun, splash with a heaped spoonful of onion mix and top with chives.

Credits: This is an edited extract from Green Burgers by Martin Nordin published by Hardie Grant Books and is available in stores nationally.

Photo Credits: This is an edited extract from Green Burgers by Martin Nordin published by Hardie Grant Books and is available in stores nationally.