This is not your usual veggie burger bulked up with beans. This is just veggies pure and simple.
1. Heat 1 tablespoon of the olive oil in a wide frying pan. Pop in the mushrooms and gently fry them, turning occasionally until they are just done – about 5-7 minutes in all. Remove the mushrooms from the pan with a slotted spoon and set aside.
2. Heat the remaining tablespoon of olive oil. Sauté the red pepper and onion rings until they start to colour, but are still crisp. Remove them from the pan and set aside. Pop in the garlic and parsley and sauté until softened and fragrant – just a couple of minutes.
3. Reintroduce the mushrooms to the pan, along with any juices that have come from them. Stir to mix everything thoroughly and season with salt and pepper.
4. Place the mushrooms on the halved rolls. If you’re having cheese, pop one slice on top of each. Then place two red pepper and onion rings on top of each, add a few slices of avocado, and finish with some mayo.