Pre-heat the oven to 190°C/170°C fan/gas mark 5
Heat the oil in a non-stick frying pan over a medium heat. Add the onions and cook for three minutes until translucent. Add the garlic and continue cooking for a further minute.
Place the onion mixture, vegetables, beans, chilli flakes, paprika, bread and cumin in a food processor and blitz until well combined. Season with salt and freshly ground black pepper. Alternatively, place in a large mixing bowl and mash together with a potato masher or fork until well combined.
Shape the mixture into four large burgers. Put the oats or seeds on a plate and coat the burgers.
Place the burgers on an oiled baking tray then brush with olive oil. Bake in the oven for 25–30 minutes until they are lightly browned and crisp on the outside.
In a separate bowl, make the salsa by combining all the ingredients together.
Place burgers in toasted wholemeal baps with rocket, slices of avocado and tomato salsa.