PORTOBELLO BURGER WITH CARAMELISED ONIONS

This recipe is from a very interesting cookbook 'Green Burgers'. It was first published in Sweden and now has been published in English. All burgers are vegetarian and there are very interesting combinations. I love mushrooms so I thought I would start with this one. I have changed it a bit, so this is my interpretation.

INGREDIENTS:

For the burgers

6 grilled and steamed spring onions

375g portobello mushrooms

vegetable oil for frying
a splash of dry sherry

5 garlic cloves, finely chopped

1 Tbsp butter

100g breadcrumbs
1/4 cup dukkah (optional)

100ml tomato sauce (ketchup)
1-2 Tbsp garlic and chilli sauce (optional)

1 egg

Caramelised onions

2 onions

2 Tbsp butter

1 Tbsp red wine vinegar

Grilled and steamed spring onions

100ml olive oil

sea salt and freshly ground black pepper

6 spring onions

To serve

120g creamy (blue) cheese

burger buns or Turkish rolls

rocket leaves

METHOD

To grill and steam the spring onions, put the oil into a ziplock bag big enough to accommodate the spring onions. Sprinkle with salt and pepper and put the bag next to the stove so it is close to hand.

Put the spring onions on a grill pan over high heat. Cook the onions all over so the surface gets a little burnt.

Using thongs, transfer the spring onions to the ziplock bag. Seal the bag and shake it so the oil covers all the onions. Leave them in the bag for about 20 minutes so they steam in their own heat. 

Chop the mushrooms very finely. Remove the spring onions from the zip lock bag and set aside. Heat the oil left over in the ziplock bag in a frying pan over a high heat until it starts to smoke. Add the mushrooms and garlic and fry them for about 10-15 minutes, stirring every now and then, until all liquid has almost evaporated. Sprinkle with the sherry and stir for another minute.

Chop the steamed spring onions (removing any burnt bits) and add them to the mushrooms in the pan. 

Add the butter, reduce the heat to medium and cook for a few minutes, stirring. 

Remove the frying pan from the heat and allow it to cool a little. Then add the breadcrumbs, tomato sauce, chilli and garlic sauce, dukkah (if using) and egg. Stir so that everything is well combined.

Divide the mixture into four parts and shape into 4 round patties, either by hand or using a food ring. Put the patties in the fridge for at least an hour, preferably longer, then they will hold together better when you fry them.

Peel and slice the onions for the caramelised onion mix. Put the sliced onions and the butter into a cold saucepan. Cook over medium heat and put the lid on. 

The onions will soon start to release liquid, and the flavours will be concentrated as a result of their cooking in their own juices. Stir with a wooden spoon about once every 5 minutes for 30-40 minutes, and check that they are not burning. (If you notice they're starting to get too dry you can add the vinegar earlier.)

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

Preheat the oven to 180C using the grill function.

Heat up some oil in an ovenproof frying pan over a medium heat. Fry the patties for a few minutes on both sides, until they develop a nice colour and a crispy surface. Transfer to the oven and grill in the oven for 3 minutes.

Put some cheese on each patty and cook for a little longer in the oven, until the cheese has started to melt. This won't take long, so keep an eye on them.

In the meantime, cut the buns in half and toast them.

To serve, carefully place a patty on the bottom of each bun. Splash on a heaped spoonful of the onion mix and top with the rocket.

Serves 4