Mexi portobello burgers with pickled pink onions

Instructions

1 To make pickled onions, in a medium bowl place onion and pour over enough boiling water to cover entirely. Leave to soak for 5 minutes. Drain and return onion to bowl. Pour over vinegar, add sugar and salt, and stir until dissolved. Set aside.

2 Meanwhile, on a baking tray or plate place mushrooms and capsicum and spray lightly with oil. In a small bowl, combine spices, then sprinkle over vegetables. Toss to coat then set aside.

3 Spray a large non-stick frying pan with oil and set over a medium heat. Add onion and garlic and cook for 30 seconds. Add beans, oregano, black pepper, and chilli flakes, if using, and stir. Cook until heated through, then remove from pan and roughly mash together. Cover and set aside.

4 Spray the same pan again with oil and set over a high heat. Cook capsicum until softened and slightly charred. Remove from pan and add mushrooms, underside facing down. Cook for about 3-4 minutes then turn. Place cheese slices on mushrooms and cook for a further 3-4 minutes until mushrooms are cooked through and cheese is melting.

5 In a small bowl, combine sour cream and coriander, reserving a little coriander to garnish. Spread equally over bun bases.

6 To assemble, place lettuce on bun bases then layer mushrooms, bean mash, capsicum, avocado, tomato and chilli, if using. Top with pickled onions and reserved coriander to finish. Place bun lid on top and serve immediately.