Rinse the quinoa and add to a pan of 300ml boiling water and a pinch of sea salt; simmer for 15 minutes.
To make the avocado salsa: combine the avocado, cherry tomatoes and onion with half of the balsamic vinegar and half of the basil and 2 teaspoons of olive oil. Set aside.
Drain the cannellini beans, place in a bowl and mash with a potato masher until all the beans are crushed.
Drain the quinoa and place in the bowl with the mashed beans, season with sea salt and black pepper and mix in the sun-dried tomatoes, black olives and the remaining vinegar and basil. Form the mix into 4 burgers.
Heat a large frying pan with 2 teaspoons oil on a medium heat. Fry the quinoa burgers for 4 to 5 minutes on each side until golden brown.